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April 2017 Newsletter

Table of Contents

Adam’s notes from the garden

In Search of a few East Texas rarities
Guest Speakers and special lectures in May
Plant of the month: the genus Tephrosia 
Slideshow of April photos

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Adam’s notes from the garden

Silene regia in the rockery

We’ve had a steady stream of visitors, both groups, and horticultural professionals, touring the garden. These tour times allow me a more thorough opportunity to keep better tabs on current highlights in the garden while sharing the joy of finding that surprise just around the path’s corner. In showing visitors around, I didn’t miss the patches of Spigellia marilandica in full flower, the inflorescence on Arisaema heterophyllum, the brief blossoms on some of our miniature cacti, and the sight and scent of another of John Fairey’s flowering Mexican Philadelphus species.

The low light casts long shadows in the dry garden north of the creek
The metallic silver undersides of Croton alabamensis var. texensis, known only from a few sites in central TX. Donated by Pat McNeal.

It’s educational to see what others find interesting that I may not focus on, but perhaps should, and to learn what excites visitors that I may interpret as “common.” One example is our Zamia floridana, the only cycad native to the U.S. In my home state, this Florida native, a durable and attractive plant known by its Seminole name “coontie,” is one of the most commonly used species in commercial landscapes. Though a staple in Florida nurseries for decades, it has never caught on here. I’m also amazed at how many visitors ask about our saw palmettos, Serenoa repens. Again, using Florida as a reference, it is abundant in well-drained soils throughout the state in both natural and cultivated settings. Many despise this palm due to the thought that snakes and other vermin inhabit the dense mass of clustering, creeping trunks, and eradication services exist on Craig’s List. John prefers our specimen – the highly attractive silver form, to be kept free of the old, dead inner leaves that tend to accumulate on wild plants, resulting in a stately and structurally bold presence adjacent to the fountain courtyard area.

Sphaeralcea ambigua ‘Louis Hamilton’
Dyschoriste linearis is proving to be a carefree xeric plant

The Magnolia tamaulipana germplasm collection has been flowering nicely the past few weeks. I think this species, native to only a couple of small natural populations, has among the most beautiful and graceful flowers of all magnolias. It is interesting to see how variable the flowers are among these different clones, which were collected as cuttings from the original trees in the wild. Visitors during the past year have been immediately struck with the abundant black spots on the leaves of all our M. tamaulipana, yet completely absent on the adjacent species of magnolias. These are strange blue-green algae(cyanobacteria) that proliferates when moist conditions are right. It causes no harm to the tree, and despite the concerning appearance, it does not draw any nutrients, just uses the leaf as a suitable surface on which to exist. It easily can be scraped off, revealing no damage to the leaf’s tissue. It is simply living like an orchid on a tree branch or moss on a tree trunk. Of course, it may be unsightly, and everyone asks “isn’t there something you can spray on it?” Even if there were a spray to kill it, the dead colony would remain adhered to the leaf, so all we can do is hope this year’s environmental conditions aren’t conducive for the recolonization on the new flushes of leaves, and the old polka-dotted leaves will naturally fall off in time. Until then, it is fun to educate visitors on the complexities of these harmless cohabitating organisms utilizing the garden as their habitat, and how everything doesn’t need chemicals, with patience and acceptance persevering.

Carpinus tropicalis, formerly identified as a Mexican version of C. carolinianus
Clematis pitcheri is native to east Texas, but this particular form was collected in Mexico

Near the fountain courtyard, visitors walk beneath a “musclewood” John collected in northeastern Mexico. This has been identified as a disjunct Mexican version of the wide-ranging Carpinus caroliniana found throughout much of the eastern U.S, with discontiguous populations occurring throughout Central America. In early April, visitors enjoyed the amazing flush of the tree’s corrugated bronze foliage which soon hardened off to green. After some scrutiny, I have recently found that this may actually be a different species that occurs in Mexico – Carpinus tropicalis. In fact, C. tropicalis was elevated to an accepted species after formerly being considered a varietal form (C. caroliniana var. tropicalis). It’s always exciting to discover a new species in the garden. 
Another mystery I want to solve is that of a Mexican collection of jack-in-the-pulpit (Arisaema sp.). I missed the flowers last year, and with its return from dormancy, it should flower soon. The foliage resembles our native “green dragon” (Arisaema dracontium), which also occurs in Mexico, but there is yet another species restricted to south of the border, A. macrospathum, with foliage that resembles A. dracontium but bears an inflorescence that has a much broader spathe – the hood-like structure that shelters “jack” in his pulpit. I am hoping to see it flower this year before my travels through much of May, and I’m also hoping the seed we produced last year will germinate.

In Search of a few East Texas rarities

By Adam Black 

A driver’s view of the dwarf plum, Prunus gracilis, forming a low groundcover on the sandy banks

With spring in full swing, I had been wanting to make a trip into the east Texas woodlands to track down some of the more unique or rare ephemeral plants, and finally, on a whim, I woke up one beautiful late February Sunday morning and decided this was the day. My target was to find the rare Texas trillium (Trillium texanum) and see if I could track down some trout lilies (Erythronium rostratum). I knew where these would be found, there would be other surprises. With some inside tips on a few recorded trillium populations, I set out on the two-hour drive eastward.

The endangered Trillium texanum

Not far from home, I noticed a roadside patch of the common Phlox pilosa that was highly variable in color, ranging from dark pink to lavender to white. The crests of hills along the way were dotted with the blue-gray foliage of emerging Baptisia bracteata, a few already starting to produce their horizontally oriented spikes of cream-colored flowers. Then, just east of Huntsville, I angered a truck driver on my tail when I had to suddenly pull over to see what the solid white carpets of flowers were that capped the sandy roadcuts. It was a dwarf plum, Prunus gracilis, which Will Fleming had told me about a few weeks earlier. These particular colonies of this extensively suckering shrub were consistently maxing out at about two feet high, creating a neat groundcover of snowy white prior to the emergence of the foliage. In the right situation, this would have tremendous horticultural potential. Also with great potential were it not so invasive was a beautiful gold leaf form of the maligned Chinese tallow tree, Sapium sebiferum.
Light rain began to fall as I arrived near the first ravine where I hoped to find T. texanum. As I hiked down a powerline easement, native azalea (Rhododendron canescens) flowers were clearly visible in the lower reaches. And as I looked off into the forest from the cleared strip of land, flowering dogwoods showed as masses of white in the distance while the copper retained leaves of American beech (Fagus grandifolia) added a warm feel to the cool late morning. Reaching the drainage, I hiked up to the source – a muddy seep, where, from my understanding, the T. texanum prefers. A good sign was the presence of Onoclea sensibilis – the sensitive fern, unfurling its new fronds. It is an indicator species for the proper habitat for the trillium. A bad sign were the extensive craters excavated by feral hogs. An extensive search yielded no signs of any trilliums.

An Itea virginica individual with exceptionally long inflorescences, worthy of selection for cultivation

Two more sites where the trilliums had been recorded also had similar destruction and were similarly unproductive. As the afternoon progressed, I gave up on finding T. texanum and decided to check out a site Georgia trillium enthusiast Charles Hunter told me has an extensive population of another more common species, T. gracile along with Erythronium rostratum. On the way, I spotted some purple flecks on a roadcut that proved to be the charming birdfoot violet, Viola pedata. This population was variable, with individuals bearing small and large flowers, with colors ranging from dark to light purple to nearly blue. One distinctive clump had a few anomalous characteristics. Normally violets have a pair of posterior petals that point upward like bunny ears. Every flower in this clump lacked those two petals, and even stranger, the erect shape curved abruptly downward like a candy cane with the flowers drooping atypically.

As Charles had indicated, the final stop of the day was indeed a surprisingly thick population of T. gracile. These were highly variable, some quite tall, some with exceptionally long petals, and some with solid green leaflets instead of the typical mottling. In between were the trout lilies, but in the waning light, the flowers were mostly closed up for the day. Mixed in were cut-leaf toothwort, Cardamine concatenata, with its white flowers held above its Japanese maple-like leaves. Though common throughout much of the eastern U.S., it is only known from a few counties in Texas, and this may be the southwestern-most population.

Trillium recurvatum with both typical maroon along with some yellow flowered forms

I had been holding off visiting a better-known population of T. texanum for a trip planned with Rick Lewandowski, director of Shangri La Botanical Garden in Orange, Texas, but our schedules did not coordinate. I didn’t want to miss them flowering, so I met up with native plant enthusiast Peter Loos several days later. But first, as an additional treat, we decided to check out one of the most southwestern populations of T. recurvatum in Texas on the private land of well-known plantsman Greg Grant, just north of Nacogdoches. Aside from being one of the more distinctive trilliums, this population harbored a few yellow-flowered forms among the typical maroon to red flowers. Also noteworthy at this site was the rare gooseberry Ribes curvatum, which has a spotty distribution throughout the southeast.

Hopefully these aren’t the last individuals of Parnassia grandiflora in Texas

We readily found the T. texanum at this particular site along a creek. There was still quite a bit of pig activity, and therefore potentially Peckerwood can help with conservation efforts in the future. Unlike the other Texas native trilliums, T. texanum has white flowers on a long arching peduncle as opposed to the other species where the upright flower is nestled tightly against the junction of the three leaflets. It is also unusual in that it prefers wet sites while the others require sloped, well-drained conditions.

Aesculus glabra var. arguta

Peter took me up to a secondary drainage of the main creek where the state’s only population of grass of Parnassus (Parnassia grandifolia) is known. Unfortunately, we did not see any plants where he remembered them to be, now quite disrupted with hog damage. Further downstream we found two individuals, hopefully not the last two in Texas. Yet another area where we should take the conservation lead before all is lost.

Penstemon murrayanus is one of the most beautiful in the genus

Peter mentioned the presence of the spectacular Penstemon murrayanus in the high sandy scrub above the creek bottom. We hiked up the hill, and he quickly found the rosettes of leaves and last year’s dried inflorescences, but no signs that they were making any attempt to flower yet. A few other interesting plants in this well-drained area were Pediomelum sp., a small ground-hugging plant with palmate, bluebonnet-like leaves and compact inflorescences with tiny blue flowers. With them was the rather uncommon Tetragonotheca ludovicianum, a member of the sunflower family with robust foliage and short yellow rays around the large central disc. Unusually large Yucca sp. were present in the scrub, some with long thin arching foliage more resembling that of a Dasylirion. In the low mesic areas, an occasional Texas variety of the Ohio buckeye (Aesculus glabra var. arguta) was displaying its yellowish green flowers.

The conjoined bracts on the erect inflorescence of Penstemon murrayanu form cups

A few weeks later, when I found myself in the region, I decided to check on the P. murrayanus to see if they were flowering yet. I tried to revisit the two Parnassia but could not find them. The area was heavily engulfed with ferns at this point, so I am hoping I overlooked them. The trilliums had begun fading, but many jack-in-the-pulpits with bold dark streaks on the inner lining of the “pulpit” were now fully up. Hiking back up the hill, I soon found the scarlet beacons of the penstemon inflorescences dotting the open sandy field. The four-foot-high flower spikes bore bracts uniquely modified into a cup that encircled the scape, giving the plant a most curious appearance. Here and there, clumps of silver hairy pinnate foliage gave rise to inflorescences of pastel yellow-green and pink pea flowers of Tephrosia virginiana, which is always nice to see.

April Slideshow

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Plant of the month: the genus Tephrosia

By Adam Black 

Tephrosia lindheimeri
Tephrosia sp. John and Carl collected in Mexico

One of my many botanical focuses that I think deserves more attention for landscape diversification and beauty are those members of the pea family (Fabaceae) that tend to be low-growing, compact, with attractive foliage and flowers. Most that fall into this category are often found in dry, well-drained conditions and therefore perfect for xeriscaping. Tephrosia is a genus I have become quite fond of for these situations. In our south perennial garden, we have a nice patch of the Texas native T. lindheimeri, which is currently flowering away with intense magenta flowers held above a spreading mat of blue-gray foliage. Even better is one of John’s Mexican collections, an unknown species with broad blue-green leaflets edged in white and erect spikes of dark pink flowers, forming a non-aggressive groundcover with a pleasing appearance even when not flowering.

Tephrosia virginiana photographed in Bastrop, TX

Native to east Texas and throughout the southeastern U.S. in fire-maintained sandhill scrub habitat is Tephrosia virginiana. Unlike the previous two, this one forms a clump of short, upright stems with fuzzy silver leaves bearing narrow leaflets. The bicolored flowers are a most distinctive combination – pastel shades of rose pink and greenish yellow. Familiar to me from Florida, I recently found a roadside population in the pinelands near Bastrop, and more recently growing with the spectacular Penstemon murrayanus near Nacogdoches. All species die back to a woody taproot in winter, vigorously emerging again in spring. Along with perfect drainage, full sun is necessary for proper growth of these species, which we hope to offer in our developing nursery in the near future.

Special guest speakers in May

By Bethany Jordan

Peckerwood Garden is pleased to present several interesting options to visit us or join us in Houston for special guest lectures in May (pre-registration required, limited space available).

May 6th join us for Garden Dialogues 2017: Artist in Residence with John Fairey. Tickets are $75.

May 9th we are proud to welcome author and horticulturist Brie Arthur for a lecture and book signing “The Foodscape Revolution”. There are few spaces remaining for this, please purchase tickets now.  

May 19th Charles “Chipper” Wichman, President, CEO, and Director of National Tropical Botanical Garden will present ” Plant Conservation and Research at the National Tropical Botanical Garden” here at Peckerwood Garden, 7 pm. Tickets are $15 for our Evening at Peckerwood Lecture series.

Also, Join us for Open Day May 13th and 27th. tickets are $10. May 3rd we will have our Peckerwood Insider’s tour of the North Dry garden and other collections located across the creek. Tickets are $15.

please contact us if you are interested in volunteering.