Palms of Northeastern Mexico

CARL MAX SCHOENFELD

126 FALL 2002 FALL Photo by Carl Max Schoenfeld

The type location for Brahea berlandieri.

NATIVE JOURNAL ABSTRACT eastern foot in the hot and humid subtropical low- lands while to the west lie Nine species of palms native to north- the cool and dry highlands. eastern Mexico are successfully grown at This topographic formation Yucca Do Nursery. These palms are easy is the perfect recipe for site- to propagate, surprisingly cold hardy, specific endemic species to and occupy biologically and geologically thrive and survive from intriguing sites. Brief descriptions of ancient times to the pres- each species and general propagation ent. techniques are provided. Politically, northeast- KEY WORDS: Brahea, Chamaedorea, ern Mexico is delineated Sabal, Arecaceae, seed propagation, cold by the states of Coahuila, hardiness Nuevo Leon, Tamaulipas, San Luis Potosi, and NOMENCLATURE: MOBOT (2002) . In these states exico ranks third in the world the following genera of in biological diversity palms can be found: (Mittermeier 1988) despite the Brahea Mart. ex Endl., M Chamaedorea Willd., and fact it is only the fourteenth largest coun- try in the world, having a land area about Sabal Adanson ex one-fourth that of the US. Mexico boasts Guersent. Continuing to about 30,000 species of plants with well narrow the scope, these 3 over 21,000 species of flowering plants. genera will be the focus of Its contribution cannot be equaled when further discussion. food crops are added to the equation, To me, the excitement Photo by Carl Max Schoenfield since Mexico is the only country where an beauty of Mexico is Figure 1 • Brahea bella. mega biodiversity and a center of agricul- unmatched. And yet, ture coincide (Ramamoorthy and others despite its close proximity standing of the characteristics that delin- 1993). Now that you have an idea of the to the US, it has been overlooked as a eate a species. This work is in progress vastness of the Mexican flora, I would source of new material. The palms and will take some time to complete. like to narrow the scope considerably and are just an example of this neglect. In The range of the Brahea complex mir- discuss the palms (Arecaceae) of north- over 100 visits to Mexico, each trip has rors that of the Sierra Madre Oriental. eastern Mexico. resulted in some new discovery. Rock palm, as species of this complex are Many different palms can be found BRAHEA COMPLEX commonly called, can be seen growing in the dramatic mountains of northeast- out of a sheer rock face only a 1-h drive ern Mexico. The awe-inspiring land- “What species is this?” This is a common south of the Texas border. They can be scapes of these mountains entice the problem when trying to identify new found clinging to exposed limestone faces senses of the plant explorer and capti- and unfamiliar plants. It is particularly of these mountains all the way south into vate the mind with hidden valleys and difficult when several very similar species Guatemala. What makes this complex so ever higher peaks. The Sierra Madre were named before sampling the entire distinctive is the incredible breadth of cli- Oriental starts its sinuous edge in population. This is the case with the mates that it inhabits while always grow- southern Mexico, and flows north paral- trunk-forming braheas. This complex ing in limestone. Imagine a 610 m (2000 leling the Gulf of Mexico, ending about includes the following species: Brahea ft) cliff with jagged edges pockmarked 160 km (100 miles) short of southwest dulcis (Kunth) Mart., B. berlandieri with rock palms growing parallel to the Texas. Here it breaks up into a series of Bartlett, and B. bella L.H. Bailey (Figure cliff surface—unbelievable! These upright isolated mountains surrounded by 1). Time will tell whether they remain trees, with smooth dark gray bark and deserts; some individual peaks reach separate species or become lumped into bright green fan-shaped leaves, share the heights of 2438+ m (8000+ ft). This 1 diverse species. In Mexico, is breeze with parrots playing in warm region of Mexico is home to many a ship that sails in uncharted waters, and 127

updrafts and captivate the imagination. FALL 2002 handsome palms, most of which remain I was privileged to lead an expedition Rock palms are about the same size as the virtually unknown outside of a few col- into Mexico with Donald Hodel, author Chinese windmill palm (Trachycarpus for- lections despite being within a day’s of Chamaedorea Palms, The Species and tunei (W. J. Hooker) H. Wendl. drive of Texas. Oddly, these represent their Cultivation (Hodel 1992). Our [Arecaceae]) and would be used in the some of the most cold-hardy palms that objective was to collect herbarium speci- same applications. However, braheas are can be grown in temperate climates. mens specifically on the palms of north- more tolerant of drying wind and This geologically divided region has its ern Mexico in order to gain an under-

VOLUME 3 • NUMBER 2 Madre Oriental. Its habitat is the oppo- site of B. moorei. Brahea decumbens Rzedowski grows on exposed limestone in a lunar-like landscape of rugged rock and rough terrain. This highly ornamental species has unique stout blue leaves (Figure 2). The 60-cm-long (2-ft) fan-shaped leaves are upright and held so close togeth- er that you cannot see their base. Very old specimens resemble an abandoned wagon wheel as the creeping trunk runs along the ground forking as it goes and, after a very long time, encircling the spot where the plant originated. These “wagon wheels” dot the landscape and help build the lean, stony soil and prevent drying winds from blowing soil away. The plant community that this plant inhabits is distinct, primari- ly made up of woody lilies (a term coined to describe woody members of the classic lily family [Liliaceae] native to the New World). These architectural plants create Photo by Carl Max Schoenfeld an unreal landscape in which several Figure 2 • The stout blue leaves of Brahea decumbens make it a desirable ornamental. species of Dasylirion Zucc. (Nolinaceae) predominate. As the plant ages, the leaves of B. decumbens turn a ghostly blue that drought. Since they are native to lime- that cut the hot sun by noon. Brahea varies with each individual but always con- stone, they are perfect for areas with moorei is a small delicate palm that has a trasts with the dark green leaves of shallow soils over limestone that would creeping habit and never forms a vertical seedlings surrounding mature plants. From stunt or kill T. fortunei. shaft. Upon maturity, it produces a chalky seeds, mature blue foliage may take up to white wax that is most pronounced on the 15 y to form. When rains are good these BRAHEA MOOREI underside of the leaf. The new leaf bud is palms produce short, stout flower stalks Whereas the Brahea complex extends over also covered in this white wax and as the and set seeds. The broad panicle is held a huge area and grows on exposed rock, leaf expands a highlight of it remains on within the leaves, which makes it difficult Brahea moorei L.H. Bailey is localized and the top of each leaf ridge. The overall to see but easy to distinguish from the thin mesic. This species is unique and cannot effect is stunning. Imagine a delicate long panicle of B. moorei. apple-green dwarf fan palm dusted with be confused with any other. Brahea moor- CHAMAEDOREA MICROSPADIX ei, although never plentiful, is found in frost and the bottoms of the leaves flocked northern Tamaulipas in the cool shade of white—beautiful beyond words. (Plants at Every year C. microspadix Burret leaves large Quercus rysophylla Weatherby Peckerwood Garden, Hempstead, Texas, are collected by the burrow-load for sale () and Quercus polymorpha are now exhibiting this characteristic after in markets all across Latin America. Cham. & Schlecht. on the eastern flank 10 y.) In the wild, goats often eat the They are used for decoration on reli- of the Sierra Madre Oriental mountain flower shaft, thus limiting its ability to gious holidays—especially Easter. Of range. This site is particularly rich in tem- produce seeds. Flower stalks are 3X the the approximate 100 species of perate flora such as platanifolius length of leaf petioles. When seen in fruit, Chamaedorea found in the New World, Engelm. ex Torr. ssp. mollis P. Fritsch this is a striking palm with long arching 2 species are native to northeastern (), Hamaemealis mexicana stalks topped with clusters of yellow fruit. Mexico and they are also the 2 most Standl. (Hamamelidaceae), Persea podade- Due to either drought or goats we have cold-hardy species one can grow in tem- nia S.F. Blake (Lauraceae), Mahonia gra- had lapses of up to 4 y before catching perate climates. In the wild, these palms 128 cilis (Benth.) Fedde. (Berberidaceae), this palm in fruit. But now, after 10 y in grow on steep slopes in the primeval Magnolia tamaulipana A. Vazquez the garden, they have flowered for the first forest facing the Gulf of Mexico in the (Magnoliaceae), and Liquidambar styraci- time. We hope that they will set viable states of Tamaulipas, San Luis Potosi, flua L. (Altingiaceae or Hamamelidaceae), seeds in cultivation. and Hidalgo at elevations of 610 to 1525 m (2000 to 5000 ft). This area is to name a few. The area is bathed in peri- BRAHEA DECUMBENS FALL 2002 FALL odic fogs before late June when the sum- home to the Huesteca, a people that mer rains settle in. The backdrop is dra- This xerophytic species is native to the descended from the Mayas, who live in matic—towering cliffs of solid limestone dry rain shadow areas of the Sierra an area that has changed very little cli-

NATIVE PLANTS JOURNAL matically. Thus it is a refugium for Although site specific in habitat, it is the predominance of S. mexicana in the plants. In the past, this part of Mexico easily accommodated in cultivation as hot dry plains and has no influence in was a giant causeway over the millenni- long as it is given shade. It is valuable the moist upland valleys. Their rate of ums—a place where flora and fauna of because it adds a striking foliage texture growth and reproduction is evidence of both the Northern and Southern and showy fruits to shady beds. these factors. Proceeding up the valley, Hemispheres met. Chamaedorea we came upon another clear running SABAL MEXICANA microspadix grows on steep, moist, rock stream but this time it cut through faces. Here you can catch glimpses of its While traveling in Tamaulipas, Mexico in solid rock folds, the foothills of the bamboo-like clumps and clusters of the late 1980s we noticed an isolated larger mountains to our west, and a bright red berries in the fading light of colony of Sabal mexicana Mart. growing rich forest. I have been to this location winter. This palm has a definite tropical in a canyon guarded by large 12-m-tall many times but until October 2001 feel about it. The large, fishtail-like (40-ft) trees that line the visitor’s view of never noticed that one of these mighty leaves flutter as moist gulf air condenses this beautiful valley. Curiously we noticed S. mexicana was variegated creamy yel- into fog on the peaks above. This trou- that this sabal population looked different low. What a find! Time spent under ble-free palm is, surprisingly, quite cold from the typical sabals seen in the coastal this tree revealed that it would be pos- hardy, surviving temperatures into the plains. Here, they grew in such great pro- sible to collect seeds of which a certain low teens ( –10 ˚C) without foliage fusion that you could not see the ground. percentage would also be variegated—a damage. In the record freeze of 1990 Palms of all sizes are seen simultaneously fact born out by the numerous varie- (record lows of –16 to –13 ˚C [3 to 8 competing for space, but here, at higher gated seedlings sprouting at its base. ˚F]) they sprouted from the ground. If altitude, the sabals stood out like solemn No matter how many times I return to you do not get enough cold to freeze totem poles (Figure 3) with only the Mexico there is always something new them back every 10 y, you will probably occasional youngster waiting its turn in to discover. need to trim them back so they do not the shade of Mexican —mostly SABAL SP. TAMAULIPAS get too tall and leggy. Quercus canbyi Trel. and Q. rysophylla. The environment is also different; instead CHAMAEDOREA RADICALIS A discovery is made! of the deciduous legume forest composed Chamaedorea radicalis Mart. is an elu- of Acacia Mill. (Fabaceae) thorn scrub we The limestone ridges and cliffs were sive jewel of temperate woodlands. A found large evergreen oaks. The stream covered with Brahea while in the dense hardy feather palm with elegant, arch- that divides the valley is surrounded by a forest below stood huge oaks and pines ing, finely divided black-green leaves, it rich and diverse understory of shrubs and towering to 24+ m (80+ ft). Here at its mimics the cycads (Ceratozamia spp. herbs. What has made these palms look most northern location, Chamaedorea Brongn. [Zamiaceae]) of the area. different from one another is subtle and radicalis makes a stunning sight. This Chamaedorea radicalis is found in the circumstantial. They are the same but area is higher in altitude (914 m [3000 deep shade of large evergreen oaks, they respond differently because of their ft]) and higher in rainfall than the peeking out and around large boul- environments. Fire plays a huge part in Sabal mexicana area. While driving ders—the perfect setting to display luminous bright TABLE 1 red fruits. Unlike Characteristics of 10-y-old palms growing at Peckerwood Garden, Hempstead, Texas C. microspadix (USDA hardiness zone 8b) that forms a bam- Leaves boo-like clump, this species has a Height Width Width Length Carried single trunk rarely Species (m) a (m) (m) (m) (number) Trunk exceeding 15 cm (6 in). This palm Brahea complex 3.5 3.9 1.5 1.5 28 1.2 m, upright is never found in Brahea moorei 1.5 2.1 1.1 0.8 20 33 cm, creeping great abun- Brahea decumbens 1.5 1.8 0.7 0.6 15 20 cm, creeping dance—just a Chamaedorea microspadix 2.4 4.6 0.4 0.8 4 1.8 m, upright scattering here 129 and there where FALL 2002 Chamaedorea radicalis 0.3 1.5 0.5 0.7 5 17 cm, upright its special require- ments can be met: Sabal mexicana 3.6 4.6 1.5 1.5 18 1.2 m, upright ample moisture, Sabal sp. Tamaulipas 2.7 6.6 2.1 1.8 12 No above ground perfect drainage, trunk deep shade, and a a Conversion: 1 m = 3.3 ft. rocky substrate.

VOLUME 3 • NUMBER 2 TABLE 2 Characteristics of germination, first true leaves, and frost protection at Peckerwood Garden, Hempstead, Texas (USDA hardiness zone 8b) First true leaves Frost protection Species Germination a

Time from Minimum germination temperature USDA to formation Size Frost cloth One pot Two pots exposed c hardiness (y) (cm) b ˚C ( ˚F) zone

Brahea complex moderate, 1 y 2 to 4 –3 (26) 6.5 (20) –9 (15) –15 (5) 8a

Brahea moorei high, < 1 y 3 to 4 15 to 23 wide –3 (26) –6.5 (20) –9 (15) –9 (15) 8a

Brahea decumbens low, 2+ y 4 to 5 15 to 23 wide 2 (36) –6.5 (20) –9 (15) –9 (15) 8a

Chamaedorea microspadix high, < 1 y 1 to 2 13 to 18 long –4 (25) –9 (15) –12 (10) –9 (15) 8b

Chamaedorea radicalis high, < 1 y 1 to 2 10 to 15 long –4 (25) –9 (15) –12 (10) –9 (15) 8b

Sabal mexicana high, <1 y 4 to 5 5 to 8 long –4 (25) –9 (15) –12 (10) –9 (15) 7b

Sabal sp. Tamaulipas high, < 1 y 3 to 4 –4 (25) –9 (15) –12 (10) –9 (15) 7

a Estimate of viability and time for seeds to begin germinating.

b Conversion: 1 cm = 0.4 in.

c Lowest temperature to which established plants have been exposed without mortality.

through this lush temperate forest we we thought that these trunkless sabals ed coming in that it was proving very found ancient specimens of Sabal mexi- were seedlings of S. mexicana until years adaptable with customers up to zone 7 cana towering into the tree canopy, but later we found these same trunkless praising its cold hardiness with no dam- every size of Sabal mexicana imaginable sabals in seed. The narrow flower spike age occurring at temperatures near –18 was present. The leaves on some of the that held the large seeds extended up and ˚C (0 ˚F). European customers reported young plants were gigantic. Some had beyond the broad blue-green leaves. The their success as well! One thing is short trunks, and others had no trunks seeds were very large and flat like an assured: our “Mexican minor” is here to but were identifiable because of the size M&M’s candy but colored a rich stay because our original plants are now of the leaves and length of their petiole. mahogany. We went back to inspect the 2.1 m (7 ft) tall and producing viable After carefully looking over the young large S. mexicana for seeds and found seeds. These seeds were planted and were plants, we spotted shorter petioled, that their old flowering branches were a offered in our 2002 catalog. The cycle trunkless sabals scattered about. As the many-branched panicle held within the has gone full course in 15 y but the iden- road cut through the forest a few of foliage. Their old flowering branch actu- tity is still a mystery! these trunk-less sabals were exposed ally hung below the leaf base, quite dif- SEEDS, GERMINATION, revealing an interesting feature—this ferent from our trunkless sabals. Could AND CARE Sabal ran horizontally on the ground these be a different species or are they while similar sized S. mexicana plunged juvenile S. mexicana flowering prema- After 10 y, all species are growing robust- their tap roots deep in the ground turely? ly at Peckerwood Garden (Table 1) and where the trunk starts its upward The trunkless sabal was numerous in several species are producing viable seeds: march. In another area farther up the this area and no trunk forming speci- Chamaedorea microspadix, C. radicalis, road we found one of the trunkless mens could be found. We gathered Sabal mexicana, and Sabal sp. sabals running off of a limestone cliff. It seeds from this trunkless Sabal and Tamaulipas. Both Chamaedorea species 130 is apparent that this trunkless Sabal planted them—they germinated quick- are prolific seed producers. I prefer to runs on the ground while its kin stays ly! We offered them in our catalogue in harvest, clean, and plant seeds promptly. put and forms a permanent root run. fall of 1990. We had previously grown I clean seeds by placing individual fruits Very old trunkless sabals were found S. minor (Jacq.) Persoon that is consid- inside a plastic bag, adding enough water that could be traced back 2.4 m (8 ft) erably slower to grow and mature than to moisten the seeds, and sealing the bag FALL 2002 FALL to where the plant originated. These old our trunkless Sabal. Affectionately we to allow the pulp to ferment. After 1 wk, trunks wear away with time while new would refer to our Mexican trunkless I pour off the excess water and ferment- roots form at the crown’s base. At first, Sabal as “Mexican minor.” Reports start- ed pulp, add fresh water and allow the

NATIVE PLANTS JOURNAL fermentation process to go again. I repeat the process as often as necessary until the seeds are clean. I place clean seeds on newspaper to dry. Clean seeds can be stored dry for several months without harming germination. I sow seeds of all species into indi- vidual pots that are narrow and deep, since the palms resent being divided from community pots. Germination varies by species (Table 2). My medium is well-drained and coarse, and I plant seeds twice their diameter beneath the mix. Soil should be kept moist during the warm months but less so during winter. At Yucca Do Nursery, we use open-end band pots that are 7.3 cm (2.9 in) wide by 23 cm (9 in) deep and made by Anderson Die and Manufacturing Co, Portland, Oregon. Chamaedorea spp. can be started in smaller pots. From my experience, the most suc- cessful time to transplant into the landscape or into larger pots is during mid spring when nighttime tempera- tures are warm and the palms are in active growth. My success is better when I keep as much soil around the root-ball as possible, spray both sides Photo by Carl Max Schoenfeld of leaves with anti-transpirant, and tie the leaves together around the central Figure 3 • A single Sabal mexicana growing at a high elevation site near Tamaulipas, bud. I keep potted transplants in a Mexico. humid area, under shade, and protect- ed from strong wind until they Brahea moorei, B. decumbens, REFERENCES become established. Chamaedorea microspadix, and C. radi- Hodel DR. 1992. Chamaedorea palms: the species At Yucca Do, we always protect calis. In addition, both Chamaedorea and their cultivation. Lawrence (KS): Allen our newly-transplanted palms the first species require shade, which enhances Press Inc. 350 p. few winters until they are acclimated. Mittermeier RA. 1988. Primate diversity and the their usefulness for potted culture. tropical forest: case study from Brazil and I add more frost protection incremen- Madagascar and the importance of the tally as the temperature decreases, ACKNOWLEDGMENTS megadiversity countries. In: Wilson E, editor. Biodiversity. Washington (DC): National starting with a frost cloth. If the tem- I thank Todd Lasseigne, PhD candidate Academic Press. perature continues to decrease, I place and assistant director of the JC Raulston [MOBOT] Missouri Botanical Garden. 2002. W 3 a plastic pot over the plant, and if the TROPICOS (on-line database). URL: Arboretum, and Don Hodel, environ- http://mobot.mobot.org/W3T/Search/vast.html temperature continues to decrease, I mental horticulturist at the University of (accessed 1 May 2002). add another pot. Critical temperatures California, for their help in reviewing the Ramamoorthy TP, Bye R, Lot A, Fa J, editors. 1993. Biological diversity of Mexico: origins and distri- for adding frost protection devices are article and especially for their expertise bution. New York (NY): Oxford University Press. in Table 2. Once acclimated, plants with the technical portion of this paper. It will tolerate very cold temperatures would not have been possible without (Table 2). For example, gallon-sized AUTHOR INFORMATION their valuable help. 131 plants of Brahea decumbens in Carl Max Schoenfeld FALL 2002 Hempstead, Texas, will freeze dead at Owner 0 ˚C (32 ˚F) while plants that have Yucca Do Nursery Inc been established for 5 y suffer no 22559 FM 359 Hempstead, TX 77445 effects at –9 ˚C (15 ˚F). www.yuccado.com Because of their small stature, 4 [email protected] species make excellent potted plants:

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