Name:             Celtis sinensis ‘Green Cascade’ 

Description:    A strongly weeping Chinese hackberry 

Range:             Zone 6-9 

Care:               Quite drought-tolerant, well-drained soil

Sun:                 Part-shade to full sun 

Propagation:   Mist propagation of cuttings taken in late spring, early summer   

Attributes:      Fast-growing, smooth bark, must be staked, easy to train 

There’s one tree in the SFA Mast Arboretum that always makes the “let’s stop-and-talk-about-it” status on our garden tours:  the weeping Chinese hackberry.  Before you scowl, curse, or take on a fighting stance, hear me out.  I know it’s got that “hackberry” label, almost a slur in the South, and I admit that this is a special use tree.  There is no blinding color show, spring or fall.  Yet, this clone is so tragically geotropically-challenged, a real leader in the anti-apical dominant movement, that it deserves some defense for its good characteristics, primarily it strong weeping nature.  Buds produce shoots with one goal: head straight to the center of the earth.  No tendrils, no twining, and no clue for this beast.  Planted on the ground without support and you’ve got a hackberry snake.  Given a high-visibility, full-sun spot – tied, propped, staked, lifted, or draped – and you’ve got a special interest tree sure to draw attention and comment from hundreds of yards around – and always a conversation piece. 

Part of what makes the clone unique is its history.  According to Cliff Parks in Chapel Hill, North Carolina, Celtis sinensis ‘Green Cascade’, was originally brought into the U.S. as part of a seed lot in 1983 (accession number 83H47).  This weeping form of the Japanese version of a hackberry is known from only a few trees in Nagano Prefecture in Japan. The tree from which Cliff collected seed (he was not allowed to take cuttings) is a national monument at Suwa Jinja shrine in the village of Kamiyamaguchimura in Nagano Prefecture.  Of ten seedlings produced, a strongly pendulous form was selected and named.  While certainly rare in the South, plants have been distributed to the gardening world by a select crowd of small to large nurseries.  

At SFA Gardens, our largest specimen separated the space between a daylily garden and the herb garden.  The leaves are a glossy green and the smooth, light gray trunk and major limbs are attractively muscled.  The Chinese Hackberry carries with it the reputation of durability and being a survivor under the worst of conditions – under good horticulture in the nursery or garden, growth is vigorous.  Propagation by pencil-sized cuttings is easiest in June (3 to 4” cuttings; avoid apical sections; 2000 PPM K-IBA dip).  Full to part shade container growth has been fast in a well-drained mix.   

This is a special use tree for a designer or landscape contractor looking for something a bit different.  In the right spot and given a little sculpting in the training years, there are few trees-that-want-to-be-vines that make quite as much of a statement as this special clone. Like all of us, it only gets better with age. 

Image of our largest Celtis sinensis at SFA Gardens

 Image of the big Celtis sinensis in Nanjing Botanical Garden, August 2015

Do dwarf Loblollies deserve a fan club?  We think so.  There’s a rarely seen form of loblolly pine – a dwarf – that needs more attention in the nursery and landscape world of the South.  Pinus taeda ‘Nana’ is a class act replacement for a number of pines that find use in the South.  With a little time and the right spot, a dwarf loblolly makes a statement like few other trees.

Let’s face it, pines dominate and define the South.  There are three main Pines in East Texas: Longleaf, Shortleaf, and Loblolly.  Loblolly pines run as far north as New Jersey, down to Florida and then all the way over to East Texas and Oklahoma.  They are everywhere.  They’re survivors, grow fast, and form the foundation of the southern timber industry.  In a good spot, they’re trouble free and low maintenance.  However, there’s a down side.  When houses pop up in their shade it isn’t long until home owners are staring sadly at 100’ towering giants with a well known reputation to fall right over into your living room.  Let’s face it.  Young pines like to lean toward sunlight and they grow fast when they’re favored.  They often are.  A house means a sunlight hole that trees push to fill.  In severe ice storms pines – particularly the long needled species – easily shed thigh-sized branches – making fine work out of anything they land on, or they simply fall over and say goodbye.    A good rule of thumb is to plant loblolly pines about 100 to 150 feet away from the house. 

Or, there’s another solution!  Well,  there are several interesting dwarf forms of Loblolly – rarely found at nurseries – that make fine specimens in time.  While rarely seen and propagated generally only by grafting, they are worth a search.  Doremus Nursery near Warren, Texas, has a stunning row of dwarf loblolly pines.  There are some beautiful trees at the JC Raulston Arboretum in Raleigh, NCSU.  I’ve seen dwarf forms on the east coast.  The late J.C. Raulston long touted the merits of dwarf adapted pines for sensible landscaping.  With a growth rate of about 20’ in twenty years, this is a specimen pine that will never threaten to smash your home, yet it will provide all the positives of a pine.  ‘Nana’ features a strong horizontal branching habit with a tendency to keep lower limbs.  It can be used as a woodland evergreen screen.  The tree form can best be described as dense and round to oval.

The dwarf loblolly is most often created by grafting a witches’ broom on a loblolly pine rootstock.  A witches’ broom is a part of a tree that displays unusually high branching and short stems. It’s often a seductive clump tucked on a branch high up in a tree.  If one can “harvest” that part of the tree (shotgun, climb the tree and cut it out, or just cut down the tree) and then graft scions to a loblolly rootstock, well, you would have a dwarf loblolly.  The root cause of a witches broom is complicated and rests with genetic changes that are often the result of some unique stress (aphids, bacteria, disease, etc.).  The seedlings of a witches broom can be but are not always dwarf.

Witches broom, image by Greg Grant

Isn’t it odd that there are so many cultivars associated with “exotic” pines – an amazing number, really – and so few with our very own natives?  P.  sylvestris, the Scotch pine, has perhaps a hundred varieties in the trade at any one time – a species, by the way, that is impossible across much of the South.  There are several dozen varieties of Japanese black pine, P. thunbergii, another species that seems to perform well here for about ten years before succumbing to one thing or the other.  So, how do exotic pines fare here in the Pineywoods?  Well, not so good.   Tip moth and beetles are the main culprits.  At one point, the SFA Mast Arboretum had 26 species of Pine that whittled down rather quickly to two exotics that survived.  One was the Himalayan pine, P. wallichiana, and the other was the Italian stone pine, P. pinea, which is quite long lived across the South.

When it comes to native pines of the South, we’ve got a long way to go in supply superior cultivars to the public.  As far as I know, the longleaf pine (P.  palustris) has no cultivars available.  The spruce pine (P. glabra) is native to South Carolina, Louisiana, and Florida and performs well across much of the South but there are no known cultivars in the trade.  What about Shortleaf pine (P. echinata)?  Well, it’s pretty much the same picture, but we do have a “weeping” form from North Carolina that is slow growing but promises great things with age.  There may be a fastigiate (columnar) form of P. echinata but it is not yet in our collection. The general conclusion here is that Pines are a foundation for Southern landscapes – and when there’s diversity available it should be evaluated and capitalized on.

Culturally, dwarf loblolly can be treated as any other loblolly.  In general, the plant responds well to full sun, a well-drained site, mulch, medium fertilizer, and irrigation during dry spells particularly in the establishment years.  Because of its nature, a dwarf loblolly pine can be recommended for planting quite close to a home or structure.  The down side of dwarf loblolly pines right now is obviously availability (in any sizes) – and their economic sense in the nursery trade.  They are occasionally available at Doremus Nursery, Warren, Texas.  Part of the problem rests in educating the public and landscapers that there are solutions to many landscape projects where dwarf Loblollies are just the right choice.

This is a seedling from a batch of seed taken from a witches broom.  Out of several dozen seedlings we chose six that are dwarf.  I think Dawn named this one ‘Little Whiskers’.

Texas firewheel is an endangered species under the umbrella of the SFA Gardens conservation program.  The mantra of our program is something we call the three R’s.  Rescue, Research, and Reintroduction.  The Texas white firewheel makes its home in East Texas in sixteen occurrences.  Gaillardia aestivalis is yellow-flowered while var. winkleri is generally white with occasional lavender to  pinkish to maroon purple flowers.  While endangered the plant is quite garden worthy and there are great opportunities for selection. 

Global Range: G. aestivalis var. winkleri is found in only one county along the West Gulf Coastal Plain of East Texas.

Texas Range: Hardin

Type Specimen: Cory 20067 (Gray Herbarium, Harvard University); Vicinity of Fletcher Lake, about five miles south of Silsbee, Hardin County, Texas, September 15, 1936.

Synonymy: Gaillardia lutea Greene var. winkleri Cory 

Current Federal Status: Endangered 

Rescue target: Gaillardia aestivalis var. winkleri is a misunderstood species with vague details of taxonomy. Also, little information is known about the current status of accurate localities, habitat structure, current distribution and range, potential range, primary threats, cultural needs, management requirements, and restoration potential.

Habitat:  G. aestivalis var. winkleri occurs in deep loose sands in openings,  sandy woodlands, and in pine-oak woodlands particularly along the unshaded margin. Herbaceous associates include Ambrosia artemisiifolia, Andropogon gerardii, Berlanderia sp., Chamaechrista fasiculata, Centrosema virginianum, Cnidosculus texanus, Croton capitatus, C. glandulosus, Croptilon divaricatum, Diodia teres, Euphorbia cordifolia, E. corollata, Froelichia floridana, Heterotheca latifolia, H. pilosa, Lechea mucronata, Liatris elegans, Monarda punctata, Panicum brachyanthum, Ruellia humilis, Schizachyrium scoparium, Silene subciliata, Solidago nitida, Stylosanthes biflora, Tradescantia reverchonii, Trichostema dichtomum, and Vernonia texana (TNHP 1993). 

General Description:  G. aestivalis var. winkleri is a perennial white-flowered variety of Gaillardia aestivalis, tap-rooted, with slender rhizomes, and is restricted to loose, white sandy soils in Hardin County, Texas. The variety winkleri does not co-occur with its closely related taxon, G. aestivalis var. flavoriens nor with the species G. aestivalis var. aestivalis.

An albino form of Gaillardia pulchella was described in 1914 by Cockerell. In a “Revision of the Genus Gaillardia” by Susan Fry Biddulph a paragraph was devoted to the white Gaillardia growing in Hardin County, Texas. Plant material was sent to her by V. L. Cory and P. A. Winkler, a landscape gardener and botanist both of Beaumont, Texas. Biddulph grew this plant in her garden and the rays and disks were pure white. She states that, “Because G. lutea has also been collected in Hardin County, Texas, the ‘white Gaillardia‘ may be only an albino form of that species” (Turner 1979).

Two collections of G. lutea, the yellow Gaillardia, are cited from Hardin County by Biddulph: the earlier had been collected at Fletcher in 1916 (Palmer 10569), and the other from the vicinity of Fletcher Lake (Cory 20067). Neither one of these collections were the yellow Gaillardia. During four years that Cory collected in Hardin County and during the many years Winkler botanized in Hardin County, neither had ever seen specimens of the yellow Gaillardia. Cory stated that “the white is not a form of the yellow as interpreted by Biddulph”. In Cory’s experience “such forms occur only along with the species” (Turner 1979).

In October, 1945, in another nearby locality the white showed a different aspect in this locality which is a tributary of Village Creek, two and one-half miles west of Silsbee, and five miles north of the other localities. Most of the plants bore white flowers (Cory 49879) but in one limited locality there were several plants with predominantly pink rays (Cory 49885).

Since Cory’s description of the variety, at least four additional collections, all from Hardin County in the vicinity of Silsbee along Village Creek have been made (Correll 31999, LL. Correll & Correll 36011, LL; Turner 9233, TEX; and Watson 1513, TEX). 

Phenology: G. aestivalis var. winkleri flowers from May-June in the spring (TNHP 1993). 

Population Biology: Information on pollinators, seed dispersal, and germination requirements is currently known by Dr. Tom Watson, University of Texas Herbarium, Austin. 

Special Identifying Features: G. aestivalis var. winkleri is readily distinguished from all other Texas Gaillardia species by its white to pinkish ray florets. No other variety of Gaillardia aestivalis occurs in the immediate area, although var. aestivalis is known in southeast Texas.         G. aestivalis var. winkleri is closely related to G. aestivalis var. flavovirens (Turner 1979). Gaillardia aestivalis  var. winkleri is perhaps closest to G. aestivalis var. flavovirens (C. Mohr) Cronq., a taxon of eastern Texas and adjacent states. It possesses yellow disk and ray florets and is a perennial with rhizomes (at least in east-central Texas). Turner (1979) stated that var. winkleri is essentially an albino population (or populations) of var. flavovirens which has undergone at least some habitat selection (white sandy soils, versus the moistly red soils wherein occurs var. flavovirens and var. aestivalis) and presumably local, if not regional, isolation.

‘Grape Sensation’ is a Dawn Stover introduction from SFA Gardens, a color form featuring purple petals.  It has enjoyed some modest success in the trade and is reproduced by cuttings (softwood cuttings under mist in June).

In fact, there’s really great opportunity to create a spectrum of petal colors.  At the Pineywoods Native Plant Center we find many seedlings featuring a range of petal colors.

LITERATURE CITED:

Texas Organization For Endangered Species 1993. Endangered, Threatened and Watch List Species. Publ. 9, Rev. 3., Austin, Texas.

Texas Natural Heritage Program 1994. Site survey summaries and element of occurrence database. TNHP Files, Texas Parks and Wildlife, Austin, Texas, USA.

Turner, B.L.  1979.  Gaillardia aestivalis var. winkleri (Asteraceae), a white-flowered tetraploid taxon endemic to southeastern Texas.  Southwest Naturalist 24 (4): 621-624.

Warnock, Michael. 1994.  Texas trailing phlox recovery plan.  U.S. Fish and Wildlife Service, Aluquerque, New Mexico.  42 pp.

Kral, R. 1983. A report on some rare, threatened, or endangered forest-related vascular plants of the South. USDA, Forest Service, Technical Publication R8-TP2. 1305 pp.

Nixon, E. S. and J. G. Kell 1993. Ferns and Herbaceous Flowering Plants of East Texas. First Edition. pp. 455. (unpublished manuscript: Dr. Elray Nixon, Red Rose Apt. 203, Las Vegas, NV).

Grogg, Cathy. 1989. How to Establish a Coordinate Locating System.  The Public Garden – the Journal of the American Association of Botanical Gardens and Arboreta (4)3: 28-31.

Murphy, D. D. 1988. Challenges to biological diversity in urban areas. In E. O. Wilson [ed.]. Biodiversity. National Academy Press. Washington, D. C. Pp. 71-76.

Wilson, E. O. 1988. The current state of biological diversity. In E. O. Wilson [ed.]. Biodiversity.  National Academy      Press. Washington, D. C. Pp. 3-18.

U.S. Fish and Wildlife Service 1991. Fifty-six animals and            plants proposed in August-October 1991 for Endangered Species Act protection. Endangered Species Technical Bulletin Vol. XVI Nos. 9-12: 8.

 

Distylium is an evergreen shrub from China, a member of the Hamamelidaceae, the witchhazel family.  While there are twelve species listed, only D. racemosum and D. myridoides are generally encountered in the USA. At SFA gardens it’s been a bullet proof shrub for many years with a history of  clean foliage in our tough climate.  It’s endured long heat waves with many days over 110 degrees F – and has come through some pretty harsh winters without a blemish (single digits).  No, it’s not going to win the color award at a plant show.  With petalless flowers and short racemes, the red stamens make the show, and while rarely dramatic, they do provide some late spring interest.  As a specimen or green screen, this species is underutilized.  In our region, we recommend part shade or at least some protection from a harsh western sun.

‘Mr. Ishi’s variegated’ remains one of our favorites, a long ago gift after a visit from the Japanese nurserymen Mr. Ishi.  It sports a unique variegation trait.  New growth is white with slivers of pink undertones which evolves into a webbing of green and white netting, which eventually fades into the green as the summer approaches.  If new growth is good in the early fall, the same thing happens.  It’s kind of a subtle beacon in the Ruby M. Mize Azalea garden.  Detractors say it looks spider mite infested.  Ignore them.

We have a variety called ‘Guppy’ that’s been at SFA for many years and it’s still a strong dwarf.  A Piroche-form looks good and enjoys strong horizontal branching, although its turning into a small tree.  Another batch of interesting hybrids we are warming up to are  ‘Vintage Jade’, ‘Blue Cascade’, and ‘Emerald Heights’.  They are seedlings from a cross of D. myricoides X D. racemosum, all Mike Dirr introductions and they can be seen at  http://www.plantintroductions.com/distyliumhybrids.html

Flowers: green and relatively inconspicuous in early spring.

Foliage: Evergreen, alternate, simple, petiolate, oblong, glossy above and glabrous beneath, often with red petioles and midribs

Exposure: Performs best in part shade

Water: Medium. Water well when young

Habit: Round and dense to fifteen high and wide

Uses: Specimen, informal hedge, mixed borders, screen.

Now here’s one to stump the most astute southern plantphile.  In the Pineywoods region of Texas, this is a durable large shrub unencumbered by the distraction of flowers, perhaps the ultimate green glob in the landscape. Almost unknown in the trade, this member of the Daphniphyllaceae is one of 15 species evergreen shrubs or trees.

This species is also referred to as the yuzuriha (meaning “deferring leaf ”) because the leaves do not fall in the autumn or winter, instead they stay attached until spring, when they ‘defer’ to new leaves. This trait is also reflected as a human characteristic, that the former generations linger until the new generation is considered ready to take their place.  The old timers waiting until they have confidence that the new generation can make it on their own.

This Asian species is hardy to Zone 7 and perhaps 6 in sheltered locations and does need protection from bitter cold, drying winds. While seldom seen, I have long admired this species for its bold look in the garden. Cooling, almost tropical, and a well-grown specimen always creates a favorable response. The species prefers a sunny location in East Texas and east across the South. Further west, the verdict is not in. For our central and west Texas fans, I would suggest part shade, a well-drained loamy soil with plenty of organic matter, and special attention to moisture in the first few years. Water quality requirements are unknown. While the plant performs best in neutral to mildly acid soils, it is reported to be tolerant of higher pH soils. We planted a row in full sun and they’re still with us but we’re quite sad during the drought of 2010 and 2011 when temperatures were consistently over 100 degrees Fahrenheit.  So we’re we.  Slow from the start, count on a 15’ X 15’ round ball in about fifteen years.

Reported to reach over 40’ in the wild, most cultivated specimens will come in at half that. There’s a closely related cousin, Daphniphyllum humile, a smaller version, that has performed poorly in our garden for some reason or another. More trials are needed. Another note of perhaps some interest, we noticed very late foliage emergence after the winter of 1998-99, a possible indication of lack of chilling. The photo below was taken several years ago near Chapel Hill, NC, in the private garden of Charlie Keith, a professor at the University of North Carolina in Chapel Hill and an adventurous gardener of many years. From a distance, the specimen resembled a giant, green basketball among the pines.

Chief difficulty in propagation has been seed source with many plants failing to fruit (pollination problems). For good set, we recommend planting three to five individuals in close proximity (10’ spacing is fine). We have run several seed sources and find the seed to germinate readily after the fruit, a drupe, has been cleaned. Cutting propagation has been another matter – we aren’t at zero success but close to it and with the variability “out there” in leaf shape, petiole and midrib color, and structure . . . there’s plenty of reason for further trials. Growth in the first few years is slow, but once established, the species is durable and appears to be quite drought resistant.

While sugar maple enjoys a sizeable market in the U.S and many cultivars are available, the Mexico mountain sugar maple or skutch maple, Acer saccharum ssp. skutchii, remains relatively unknown. This disjunct wing of sugar maple has endured over 9000 years of divergent evolution apart from relatives in eastern North America (4).  The tree is similar in many respects to Acer saccharum, sugar maple, and Acer saccharum var. floridanum (syn. A. barbatum), the Florida maple, but features larger leaves, and perhaps the biggest samaras found in Aceraceae.  The skutch maple offers opportunities for enhanced growth rate, interesting fall and spring foliage color, alkalinity tolerance, drought tolerance and good adaptation to well drained sunny locations in landscapes of the southern USA, east to west.  Dirr lists 47 varieties of sugar maple in the industry (1).  None include the diverse genetics of this western relative, the skutch maple of Mexico.

 

 Nature of Work: SFA Gardens comprises 128 acres (52 ha) of on-campus property at Stephen F. Austin State University (SFA), Nacogdoches, Texas.  Initiated in 1985, SFA Gardens focuses on diversity, collections, rare and unusual species and cultivar collections, and promotes plants that perform well in East Texas and Louisiana landscapes.  SFA Gardens has an extensive collection in the Aceraceae, with western genotypes well represented. The skutch maple is a genetic resource for breeders interested in improving growth rate, and drought, heat, and alkalinity tolerance.

Background:  In 1993, Simpson and Hipps assigned nine, possibly ten, maples to the southwestern USA (6).  They noted that certain provenances of A. grandidentatum, Bigtooth maple, and the Caddo maple, a unique genotype of A. saccharum from southwestern Oklahoma, were particularly good performers in higher pH soils.  Skutch maple, or the cloud forest sugar maple, Acer saccharum ssp. skutchii, is the least known in the USA and is the southern and western most sugar maple.  It occurs naturally as six disjunct populations, with five in Mexico and one in Guatemala (7).  First described in Guatemala in 1936 (5), the skutch maple is a rare relic from the Miocene era, probably separated from those in North America since the end of the Pleistocene over 9000 years ago (4).  Lara-Gomez characterized variation in isolated skutch maple populations in Mexico (2).   Yalma Luisa Vargas-Rodriguez, who graduated from Louisiana State University in 2005, hypothesized that the “six forest sites in Jalisco, Tamaulipas, Veracruz, and Hidalgo (Mexico) contain a unique and ancient flora, were connected and shared species before the Pleistocene, and currently function as tree refuges of that ancient flora” (8). Because of the small number of populations and low numbers in each population, Vargas-Rodriguez proposed to include Skutch maple in the IUCN Red List Catalog and as Endangered in the Guatemalan Species Red List.  In fact, it’s even a bit more complicated.  In a recent visit here at the SFA Gardens, I learned that Yalma believes the Jalisco population should be considered a brand new species, Acer benzayedii.

SFA Gardens Research:  The oldest skutch maple at SFA Gardens was planted in 1994 and originated from seed collected in the Tamaulipas location (3) by John Fairey and Carl Schoenfeld of Yucca Do Nursery, Hempstead, Texas. Now twenty years old, the tree is 46 ft (14 m) tall with an 18 in (45.7 cm) diameter at breast height (dbh).  It has grown well without irrigation, is oval shaped, exceptionally marcescent, and failed to develop showy fall color until after first flowering, an event that took 9 years to initiate.  Fall color varies between butterscotch yellow to reds and oranges, depending on year.

 

Propagation:  The samaras are large and showy.  In our location, seed are often empty, with viable seed at less than 10%.  In 2009 the tree produced a heavy seed crop and we allowed the samaras to fall and then covered the area with an inch of pine bark fines.  The end result was over one thousand seedlings emerging early (January) that were not affected by frosts in February.  Seedlings were potted, grown and distributed to interested nurseries and university research programs.  In our trials, cutting propagation of young seedling trees is feasible because of their juvenile nature.  Still, after numerous cutting batches, we have noted a poor <20% rooting/survival rate. Best results are two node June cuttings using 1500 PPM K-IBA as a ten second basal end dip.       

Research Plots:  In January 2011 SFA Gardens established 277 skutch maples at SFA’s Science Research Center which is about five miles north and west of the campus.

 

The seedlings for this project were progeny of our sole flowering tree.  The pollen source is unknown.  However, there’s some reason to suspect self-pollination.  First, sugar maples are generally considered to be wind-blown self-pollinators. While I’ve noticed bee activity on the Skutch maples and on our native maples, many researchers think that’s artifactual and wind is the primary mode of pollination.  It’s complicated.  Second, the flowering time of the skutch maple is slightly earlier than nearby Florida maples.  Third, the performance of seedling batches in central Texas indicates a degree of alkalinity tolerance not shared by Florida maples.  However, there remains the possibility that the distributed trees are hybrids with our local Florida maples.  The goal of this project was to improve on seed availability, improve seed set and viability, and to select superior clones.  This is a cooperative project with SFA’s College of Science and Mathematics through an informal agreement to use unutilized space at the Science Research Center for plant evaluation.  The site is a full sun south facing gentle slope with a red clay loam (pH 6.7).  SFA Gardens planted the seedlings spaced 15 ft (4.6 m) X 15 ft (4.6 m).  Over the last three years, weed control has been backpack sprayer applications using glyphosate.  The field drip irrigation system utilized ¾ inch black poly pipe with ½ gallon per hour emitters and a battery operated controller which delivered one to two gallons per plant per day during the irrigation season.  The trees have not been pruned except to allow easier mowing and glyphosate application.

Fig 2.  Skutch maple plots at SFA

Climate:  Nacogdoches is in Zone 8B of the Pineywoods region in East Texas with an average annual rainfall of 48 in (122 cm).  June through August is characteristically hot and dry.  1 Sept 2000 was the record high, 112 F (44.4 C), and 23 Dec 1989 was the record low 0 F (-17.8 C). In 2010 and 2011, Nacogdoches experienced all-time record drought and heat.  Total precipitation in 2010 was 22.3 in (56.6 cm) and 2011 produced 35.4 in (89.9 cm), with one third of that that coming late in the fall.  Fortunately, 2012 and 2013 saw a return to normal summer temperatures and rainfall at 59.6 in (151 cm) and 43.4 in (110.2 cm), respectively.  

Performance:  Growth rate has been excellent.  Trees were planted in January 2011.  After three growing seasons, a 24 June 2014 random sample of 32 trees indicates an average tree height of 17.7 ft (5.4 m).  The tallest trees exceed 21 ft (6.4 m) in height and 4.5 in (11.4 cm) in diameter.  Diameter at six inches averaged 2.9 in (7.4 cm).  This random sampling did not include any replants or damaged trees.  Deer have been a constraint at this site, not through browsing but through bucks rubbing their racks on young trees.   Over the past three years we have replanted 23 trees due to extreme deer damage.  In other cases the trees sprouted vigorously below the damage and a new leader was chosen to restore the tree.  

Results:  This seedling block includes significant diversity.  For instance, we note an 11 day variation from earliest to latest leaf emergence in the spring.  There is great variety in the color of new growth (green, yellow, red, salmon, pink).  Fall foliage color has been brown with leaves held tight into January before falling.  However, there is evidence this species does not characteristically develop good fall color until after flowering.  Most trees are not of good habit with haphazard branches, a tendency to multi-leader, and bad crotch angles.  However, in this seedling block, there’s a variety of forms, including several fastigiate forms, one dwarf, and others with tighter habit and good shape.   We have cutting propagated twelve selections and will be multiplying others in the next few years.

Fig 3.  Spring growth

Genetic characterization. Very little is understood about the genetic diversity in this species.  Von Gomez noted that this rare endemic is only known from six locations. They observed the variation in three small populations from two locations.  Total variation was low.  The smallest pop at Manantlan with only 26 plants revealed the least genetic diversity.  Von Gomez suggested focusing on larger populations for in situ conservation work, and creating a plantation from all the populations to capture the maximum amount of available diversity.

SFA Gardens is cooperating with Jason Grabosky, Rutgers University, New Brunswick, New Jersey in a maple characterization study.  April Jackson, PhD candidate, is investigating variation within and among taxa included in the hard maple group. In particular, she is studying Acer saccharum, Acer nigrum, Acer barbatum, and Acer leucoderme. Populations of Acer grandidentatum as well as Acer skutchii were also represented in these studies. April is studying morphological, anatomical, and physiological traits that may enable species tolerance to water deprivation and increasing temperatures. She is genotyping germplasm collected over the last three years across natural ranges of the taxa to determine how genetically similar (or not) these taxa are. She will use phylogenetic analysis to address taxonomic discrepancies within this group of taxa and hopes to resolve classification and nomenclature listings.  We are also cooperating with Richard Olsen of the National Arboretum, Beltsville, Maryland, in a similar project.  In 2015, we hope to sample both our research plots and trees known to have originated from Mexico seed to determine parentage.  Finally, our long term goal is to acquire seed of other provenances in Mexico, and, hopefully, Guatemala, to develop a documented ex situ collection of this species at SFA Gardens.

 Cooperator observations  

Brent Pemberton, Research Scientist, Texas Agrilife Research and Extension Center, Overton, TX:  “We’ve had Acer skutchii in the ground for one full growing season.  Looks good but still a small tree.  It did survive all the cold weather this past year including 16^oF on Mar 3 after only being in the ground for one season.”

Paul Cox, San Antonio Botanical Garden, San Antonio, TX (retired):  “Acer skutchii at the SABG has put on the same height growth as Taxodium mucronatum during the first 10 years. It’s fast. Leaves have never scorched but don’t have the dramatic fall color reported from other areas.”

James Spivey, nurseryman, Peerless Nursery, Bigfoot , TX:  “Acer skutchii has a great deal of potential in the tree market for the Central and South Texas. It seems to be very tolerant of alkaline soil around San Antonio and the Hill Country. It has been very tolerant of heat and direct sunlight without any burning of the foliage. The growth rate has been 3-1/2′ to 4′ per year under irrigation.”

Mike Arnold, Research Scientist, Texas A & M University, College Station, Texas:  “Nice plant in areas without saline soils or irrigation water.  We have killed it repeatedly in multiple locations here due to the salts in the irrigation water.  Chlorosis due to alkalinity does not appear to be nearly as serious as the salts.  It develops the classic marginal necrosis and then dieback and death.  It just is intolerant of the salts.”  In an earlier correspondence, Mike reported Acer skutchii had failed to deal with the high salinity irrigation water in College Station (250 PPM Na and 500 PPM bicarbonates).  Whether irrigated by drip, sprinkler or microsprinklers, plants performed poorly.  Leaves were cupped and took on a bluish cast, and the trees failed to survive in their container trials.

Steve Lowe,  Naturalist, Kendall County Park. Boerne, TX:  “Acer skutchii is remarkably well adapted for this area. After visiting these trees in their home range, it is easy to see their affinity for limestone.  They are truly saxicolous. This would explain their tolerance of our high pH soils, outperforming even our native Bigtooth maples. Skutch maples I’ve planted in this area have consistently grown 3-4+ feet per year with only moderate irrigation. As with the Sierran oaks, new growth is extra early here, pink/brown and sometimes subject to cold damage. Most here attain peak color end of December (citron to canary yellow to pumpkin). Foliage color and texture (more leathery) seems to change as tree matures.”

Jim Robbins, University of Arkansas, Little Rock and Hope, Arkansas: “In 2011, twelve one quart plants were donated by SFA Gardens. One plant died at Little Rock in the first growing season and a second in year two.  Average height at Hope and Little Rock is 11.2 ft (3.4 m) tall with a trunk caliper at 6 in (15.2 cm) of 5 in (12.7 cm).  The growth habit might be a challenge in nursery production since the tree produces extremely vigorous shoots that require pruning and training. Based on observations at Little Rock (Zone 7), we’ve observed no dieback during this past harsh winter (9 F) low.”

Eric Hammond, Heritage Seedlings, Inc., Salem, Oregon:  “We have one tree in the grow-out area. It is the only example I know. And though, I know Mark Krautmann is enthusiastic about this species because of its broadly adapted nature, I will not lie about our tree.  It is hideous in form, growing off at all trajectories like a North Korean rocket test. Marks in its favor are perfectly clean foliage of great texture, though they are puckered much more than I prefer, and no twig damage of any sort after a freeze. So in short I see a tree of little merit for our climate where we have an overabundance of choice but if it is adapted to the SW market I think it is a plant we can produce successfully.”

Matthew Chappell, University of Georgia Horticulture Department, Athens, GA:  “It’s doing well in GA – no fruit yet but I have it in container and in-ground. Last year was an establishment year and this year they are jumping out and growing like crazy. We did have some tip dieback but can’t even tell now (we went to 5.5 F).

Mike Dirr, Plant Introductions, Inc., Watsonville, Georgia:  “I’m not sure I can verify hardiness but no issues at 6 F; early fall freezes, 22 F two nights running November 13 and 14, 2013; and a late spring freeze April 16, 2014, 29.5 F. I have three in the garden and all are vigorous (3 ft/year on average) with pretty reddish tinged new shoots. It’s certainly heat tolerant and a good fall colored selection would be a valuable contribution to the southern palette of landscape trees. Species needs to be domesticated like sugar and red maples.”

Tom Cox, Cox Arboretum, Canton, Georgia:  “A. skutchii has been a solid performer here in north Georgia. It takes the heat and humidity without showing any stress and easily survived 2 F  degrees for several days this past January. Leaf retention in the fall is longer than either A. saccharum, rubrum or nigrum ‘Green Column’ and it colors up later. I like this as it extends fall color in the arboretum.  During the spring and summer, it is thus far unremarkable. Its leaf appears pathogen free and is still clean at time of absicission. The leaf is smaller than anticipated so I’m wondering if my two trees might have some mixed parentage.  I would rate its vigor as moderate, although this might change as it forms a deep taproot. This suspicion is based on my experience with Acer nigrum which took several years before it took off and is now a fast grower.”

Mark Weathington, JCR Arboretum, Raleigh, NC:  “We have had mixed success.  We lost our oldest plant this winter but it was not a cold issue.  That tree had been declining for years, had some canker issues and just generally never looked very good for as long as I’ve known it.   We received a plant from you in December 2007 that was 15 in (38 cm) tall.  It was planted spring 2008 and when last accurately measured in 2012 was 20 ft (6.1 m) tall with a 10 ft (3.0 m) spread.  It has put on at least 5 ft (1.5 m) since then.  It is growing in a very loose soil that has almost prefect drainage for excess water but still retains moisture well but leaves lots of air space.  It seems to perform best for us in this type of situation (what doesn’t?) but doesn’t fare quite as well in very heavy soils where growth is much slower.  We had no winter damage at 7.5 F (-13.6 C) this winter and we have not had issues in other winters with it leafing out early and getting hit by later frosts.  So far, we haven’t had great fall color on any of our trees.

Results and Discussion

 Besides conservation of rare maple genetics, there are horticultural reasons to capitalize on skutch maple traits that might benefit progeny.  Certainly, fast growth rate and drought tolerance is in line with the long term trend facing the southern USA, a warmer and perhaps drier climate.  Alkalinity tolerance may create opportunities in regions where sugar maples often fail.  Certainly, cooperator and our own observations reveals trees exhibiting negative branching habit, poor form, multi-leaders, and a training problem for nurserymen.  However, there is variety in form and habit; we have selected a dozen for improved form, new growth color, and height/trunk diameter characteristics.  Those will be planted for further evaluation.  Fall color selections are years away.

  Literature Cited

1. Dirr, M. 2009.  Manual of Woody Landscape Plants.  Stipes Publishing, Champaign, Ill.:  67.
2. Lara-Gomez, G, Gailing, O, Finkeldey, R.  2005.  Genetic variation in isolated Mexican populations   of the endemic maple Acer skutchii Rehd.  Allgemeine Forst Und Jagdzeitung  76 (6). Jun-Jul 2005.p.97-103 J D Sauerlanders Verlag, Frankfurt.
3. Efraim Hernandez X, Howard Crum, Wm. B. Fox and A. J. Sharp.  1951.  A Unique Vegetational Area in Tamaulipas.  Bulletin of the Torrey Botanical Club Vol. 78, No. 6 (Nov. – Dec., 1951), pp. 458-463.
4. Paul S. Martin and Byron E. Harrell. 1957.  The Pleistocene History of Temperate Biotas in Mexico and Eastern United States.  Ecology, Vol. 38, No. 3 (Jul., 1957), pp. 468-480.
5.  Rehder, A., 1936.  A new species of Acer from Guatemala. Jour. Arnold Arbor 17: 350-351.
6. Simpson, B. and B. Hipp. 1993.  Maples of the southwest.  American Nurseryman 177(5): 26-35.
7. Von G. Lara Gomez, O. Gailing, and R. Finkeldey.  2005.  Genetic vafriagtion in isolated Mexican populations of the endemic maple Aceer skutchii Rehd.  A..g. Forst- u. J. Ztg., 176. Jg., 6/7″ n97 – 103.   
8. Yalma Vargas-Rodriguez and William Platt.  2012.  Remnant sugar maple (Acer saccharum subsp. Skutchii) populations at their range edge: Characteristics, environmental constraints and conservation implications in tropical America.  Biological Conservation 150: 111-120.
9. Yalma Luisa Vargas-Rodriguez.  2005.  Ecology of Disjunct Cloud Forest Sugar Maple Populations (Acer saccharum ssp. skutchii in North or Central America.  PhD dissertation, Louisiana State University and Agricultural and Mechanical College, Department of Biological Sciences, Louisiana State University, Baton Rouge, La.  http://etd.lsu.edu/docs/available/etd-07152005-083738/unrestricted/Vargas-Rodriguez_thesis.pdf.

Dave Creech, Director SFA Gardens – dcreech@sfasu.edu

Planted in 1988, this is our oldest Quercus rysophylla, the loquat-leaved oak of Mexico.  It is now over 18 m. (60 ft.) tall, has a dbh of 52 cmsa striking specimen in full sun.

Two years after establishment the tree endured the record Dec 23 1989 -18^oC (0^oF) hard freeze.   The tree never blinked.  Keep in mind that this was back when the Mexico oaks were relatively untested in Texas and parts north and there was an assumption that they might not be able to deal with our colder clime.  Not so. In fact, the loquat-leaved oak does quite well in states to our north particularly if established a few years in the ground.  Our big tree was hit with two hurricanes in 2005 (Rita) and 2008 (Ike).  Record heat and drought in 2010 and 2011, the worst on record, didn’t faze the tree.  Through all this, the tree has never missed a beat.  Evergreen in our climate, the thick, rough leathery leaves are dark green and glabrous, 6-22 cm. (2–8.2 in.) long, elliptical to oboval-lanceolate.  New growth varies from copper to salmon color and old leaves are shed quickly in late winter or early spring.  The tree has never been affected by tent caterpillars, which have occasionally ravaged the nearby native oaks in the garden and on our campus.

When measured in 2016, the tree in the SFA Mast Arboretum was 64″ in diameter (20.2″ dbh) and is one of the largest in the nation.  However, the big one at Peckerwood, Hempstead, TX, was recently measured by Adam Black and came in at 68.5 inches ( 21.6″ dbh).   Is this the national champion?  No, I think the one at Peckerwood is.

 

A recent visit (12-31-2016) to Peckerwood, Hempstead, TX, let me hug the big Q. rysophylla there and while I didn’t get a measurement I think it’s the National Champ.  Adam Black is the new Horticulturist and he brings a breath of fresh air to the incredible garden built by John Fairey.

Native to Nuevo Leon, Tamaulipas, and San Luis Potisi, this species is usually encountered in the mountains at mid to lower elevations.  A tall tree, this species can reach over 25 m. (82 ft.) in height.   Acorns are small, 1–1.5 cm. (.4 to .6 in.) long, pointed, in singles to several on a stout peduncle with the cup enclosing about 1/3 to ½ of the nut.  In our region, the tree performs best in a well-drained soil and full sun.  While often spelled rhysopylla or risophylla, we have chosen to reflect the original spelling by Weatherby (Weatherby, 1910), Q. rysophylla.

Acorns germinate readily and in our garden seedlings are usually true to type, although occasional hybrids are found; these are easy to segregate after the first year.  One particular seedling selected for nice form and branching from a batch years ago was planted along LaNana creek  and is very dark green.

 

Weatherby, C.A. 1910.  Quercus rysophylla. Proc. Amer. Acad. Scie. 45: 423.

David Creech, SFA Gardens, Arthur Temple College of Forestry and Agriculture, Stephen F. Austin State University, Nacogdoches, TX –  dcreech@sfasu.edu

Indian Pink–Spigelia marilandica–is one of about 50 species of mostly herbaceous perennials of the family Loganiaceae from mostly tropical and warm areas. This is just about the hardiest of the lot and it’s the best a Pineywoods native can offer. I love this plant; I always have. My first memory of a colony goes back over 30 years to a lazy afternoon excursion with Lynn Lowrey near Kirbyville, Texas. We drove one of the better blacktopped FM roads in Newton County and I remember climbing a small hill and over the top and then down to a sun-lit swag with a small stream at its center.  It was in that moist wet spot that Indian pink had found a home – about the prettiest colonies of Indian Pink one might imagine. It was no more than a couple of hundred square feet, but it was a pure stand, and it was flowering with amazing force.  The best landscape home for our native Indian pink is a moist, rich, humic forest with protection from the harsh western sun. Skip twenty years and I was nervously trying to find the home of a Shreveport gal to take to Akin’s nursery, our very first date.  It didn’t take me long to realize her talent was not in giving directions but I finally found her home and when I pulled up, there she was by the prettiest clump of Indian pink ever.  I’m still not sure who wins this beauty contest, the Indian Pink or Janet.   We’ve been together ever since.Once well established, Indian Pink is really a rather reliable returning herbaceous perennial in our area. It grows as a rhizomatous clump between one and two feet high, with about a one to two foot spread. It has supple, sometimes glossy dark green foliage that persists throughout the growing season. From late spring into summer, it bears many upright, tubular, bright crimson flowers with light yellow throats. The plant can be made to rebloom more vigorously if lightly pruned after the first flowering event – blooms on new wood.  The five-lobed tips of the flowers open gradually and look like small cream-colored stars perched on red pedestals. In bloom, no plant has greater grace and charm. Under good culture, leaves are robust, clean, and dark green. We need more Indian pink in the shady spots of East Texas landscapes simply because of the charm of genuine native treasure.

For bird lovers, Indian Pink is thought to be a major nectar source for ruby-throated hummingbirds, and it has been voted one of the top ten hummingbird plants in the country by Operation RubyThroat, an international research and education initiative based in York, South Carolina.   For the herbal crowd, the genus Spigelia is considered medicinal with attributes as an antihelmintic (vermifuge). In fact, any search of the Web will find buckets of Spigelia products touting anti-headache attributes. The only headaches we’ve had have to do with propagation:  the plant is a bit tricky. Asexual propagation is the norm in the trade with a preference shown for selecting the most vigorous tips as cutting material. The vegetative cuttings are often a bit turgor-difficult and mist propagation requires attention to detail.  Easy to damp off, propagators should use a light mix with mist intervals frequent enough to prevent first wilt.  Because of high demand and lack of supply, the plant is now becoming more and more available from the tissue culture world.  The end result is that plants are available for anyone willing to seek them out.

Other related species include S. texana (syn. S. loganoides or Florida Pinkroot) and S. gentianoides (Gentian Pinkroot). Neither is in cultivation right now, but S. texana, a white-flowering species, is reported to have potential as a groundcover.  S hedyotidea, Priairie Pinkroot, is native to the southern and westerns parts of north central Texas and is normally found on limestone outcrops and gravelly soils; this species is even more uncommon than Indian Pink. Further to the east in Florida and Alabama, the pale-pink-flowering S. gentianoides is so rare it’s on the federal list of endangered species. Evidently pressure from agriculture and forestry has been a main threat and the plant is limited to a small number of populations in Florida and Alabama. Conservation efforts are under way at the State Botanical Garden of Georgia, in Athens, Georgia. S. splendens is reported in Mexico and Guatemala.  In terms of landscape and medicinal interest, Spigelia is a genus worth exploring.  The PNPC is working to build a collection of Spigelia genotypes from the Pineywoods and states further east.  We promote this plant at most of our plant sales, a native deserving much greater use in the landscapes of the South.  Once established, it’s bulletproof.