THE CACTI OF BIG BEND NATIONAL PARK

17 THE CACTI OF BIG BEND NATIONAL PARK K E N N E T H D. HEIL A N D STEVEN BRACK San Juan College, Farmington, N M over entire joint, sometimes fewer and shorter in lower areoles, light brown to bright-yellow, orange-brown to nearly black, all with yellow tips; main spines (1-2)3-5(6) per areole, sometimes flattened and twisted, 2-6 cm long, basally up to 1.3 m m broad; 1-7 slender accessory spines, same color as the main spines, up to 2 cm long; apex of the mature bud pointed, acute, conical, outer perianth segments green with reddishbrown tips and pale margins; ovary at anthesis mostly 3-4 cm long, 1.5-2 cm in diameter with leaves up to 4-5 m m long, 1.5 m m diameter, pointed at the tip with yellow to orange glochids, low elongate tubercles on the surface of the calyx of the unopened bud with up to 8 yellow to orange spines per areole; flower mostly 6-8 cm long, 6-7 cm diameter, 19-23 perianth segments; sepaloids with greenish centers and brownish tips; petaloids yellow, usually with bright orange or Opuntia macrocentra Engelm. var. aureispina red bases, obovate, up to 4 cm long, 5 cm dibrack & Heil, var. nov. ameter, tip mucronate, apical margin erose; pistil 2 cm long; style 1.2-1.3 cm long, yellow, often Magna opuntia recta usque ad 1 m alt.; caulis sinpink at base; stigma lobes 6-8, up to 7-8 m m gularis spinis tectus ramis plurimis prope terram et ascendentibus; segmenta viridicaerulea ad flavoviren- long, green; fruit 3-4 cm long, 2-5 cm in ditia, glauca, orbiculata ad obovata 8-12 cm long., 8-12 ameter, fleshy, green to slightly reddish, soon cm lat., 1 cm crass.; areolae separatae 18-25 mm; spi- drying to a hard tan bur covered with rigid spines; nae super segmenthum totum, interdum pauciores bre- seeds tan, 3-6 m m diameter, 1.5-2 m m thick, vioresque ad areolas inferiores, bruneolae ad aureas, irregular shape with a narrow rim. cinnamomeae ad piceas, omnes apicibus citrinis; spitype Locality. Near the Rio Grande River, nae principals, (1-2)3-5(6) per areolam, aliquando complanatae torsivaeque, 2-6 cm long., ad 1.3 mm lat. Big Bend National Park, Brewster County, Texbasi; 1-7 spinae graciles accessoriae, colore eodem atque as. Distribution. Limited to Big Bend National in principalibus, ad 2 cm long.; apex gemmae naturae acutus, conicus, segmentis exterioribus perianthii vi- Park, so far as known. Grows on Boquillas Limeridibus apices prophyreos et margines pallidos haben- stone slabs and fractured limestone rocks in the tious; ovarium per anthesin vulgo 3-4 cm long., 1.5- desert flats at 575 m (1,900 ft) elevation. 2 cm diam., foliis 4-5 mm long., apice acutis, glochiholotype. Deposited at San Juan College Herdibus flavis ad aurantiacas, tuberculis humilibus elongatisque in superficie calycis gemmae inapertae et us- barium under the number SJNM 377 While doing a comprehensive cacti study for the National Park Service we found a new golden-spined prickly pear cactus in the southern portion of Big Bend National Park. This new species is known only from a very small area growing in desert flats of limestone origin. It grows in association with Agave lechuguilla, Bouteloua breviseta, Euphorbia antisyphilitica, Jatropha dioica, Coryphantha ramillosa, and Escobaria duncanii. T h e plant grows at approximately 575 m (1,900 ft) and as far as known is restricted to Big Bend National Park, Brewster County, Texas; however, it probably extends south into Coahuila, Mexico. This new species seems to be a relative of Opuntia spinosibaca Anthony which also grows in the area. There appears to be no hybridization between the two species. que ad 8 spinas flavas ad aurantiacas per areolam; flos plerumque 6-8 cm long., 6-7 cm diam., 19-23 segmentis perianthii; sepaloides centris subviridibus et apicibus subumbrinis; petaloides flavae, plerumque basibus croceis aut rubeis, obovate, ad 4 cm long., 5 cm diam., apice mucronato it margine apice eroso; pistilum 2 cm long.; stylus 1.2-1.3 cm long., flavus, saepe roseus basi; lobi siigmatis 6-8, usque ad 7-8 mm long., virides; fructus 3-4 cm long., 2-5 cm diam., carnosus, viridis ad rubellum in testam aculeatam duram subspadiceamque spinis rigidis tectam mox siccans; semina suspadicea, 3-6 mm diam., 1.5-2 mm crass., forma irregulari margine angusto. Large, upright prickly pear up to 1 (1.5) m high; single trunk densely covered with spines, numerous branches near the ground and ascending; joints light blue-green to yellow-green, glaucous, orbicular to obovate, 8-12 cm long, 8-12 cm broad, 1 cm thick; areoles 18-25 m m apart; spines Escobaria tuberculosa (Engelm.) Britt. & Rose var. varicolor (Tiegel) Brack & Heil, comb, nov. Coryphantha varicolortiegel, Monatsschr. Deutsch. Kakt. Gesellsch. 3:27 193 Biologically we think that this taxon is part of the Escobaria tuberculosa complex. It makes a regionally pure population in the Marathon Basin, giving credibility to distinction at subspecific rank. In the park, E. tuberculosa grows in pure stands at lower elevations favoring limestone rocky slopes, primarily along the Rio Grande River. At higher elevations, e.g., in the Chisos Mountains, E. varicolor is found in pure stands. The two plants have intergradation zones, primarily from the north side of the Chisos to the north central parts of the park.

18 Fig. 1. Chisos Mountains. Photo by Ken Heil. Ah yes, Big Bend National Park! What a contrast in vegetation zones that vary from the Chihuahuan Desertscrub to the Madrean Evergreen Woodland (Brown and Lowe, 1982) and at elevations from 550 to 2,350 m (1,800-7,800 ft). Big Bend National Park is located in southwest Texas where the Rio Grande arcs southward into the Mexican states of Chihuahua and Coahuila. Desert and mountain land (708,221 acres) was established as Big Bend National Park on 8 June Fig. The Rio Grande River at Santa Elena Canyon. Photo by Ken Heil. Fig. Near Trap Mountain; Agave lechuguilla. Photo by Ken Heil. 194 The park headquarters, Panther Junction, is located approximately 112 km (70 mi) from Marathon, Texas on highway US 38 Another paved highway runs east-west from Study Butte to Rio Grande Village. Rio Grande Village has gasoline, groceries, campground/recreation vehicle facilities, and showers. A paved but winding road leads into the Basin of the Chisos Mountains. The Basin has a campground, restaurant, store, and lodging, and is the starting point for many mountain hiking trails. Another paved road goes from Santa Elena Junction to Castolon and continues to the Santa Elena Canyon Overlook. Gasoline, a store, and a nearby campground are at Castolon. Lodging and food service facilities are also available in nearby Terlingua and Lajitas. Two improved dirt roads in Big Bend National Park include Old Maverick Drive and Dagger Flat Road. There are several backcountry dirt roads to explore in the park that require high clearance vehicles and/or four wheel drive. These include River Road, Old Ore Road, Glenn Springs Fig. Opuntia macrocentra var. aureispina is a rare golden-spined prickly pear found in the extreme southern part of the park. Photo by Thomas S. Sawyer.

32 mington, New Mexico; reviewers Charles Glass, Robert Foster, E. F. Anderson, David Schleser, Larry W. Mitich, Mark Porter, Marilyn Heil, and Estelle Morin. We are grateful to Mrs. Nancy Lawrence of the Career Enrichment Center, Albuquerque Public Schools, Albuquerque, New Mexico for her preparation of the Latin description. Special gratitude is expressed to Dave Ferguson who helped labor through the writing of the taxonomic keys. References Anderson, E. F. 198 A revision of the genus Thelocactus B. & R. Bradleya 5:49-7 Oxford. Backeberg, C. 197 Cactus lexicon, 3rd ed. Blandford Press, Poole, Dorset, England. Benson, L. 198 The cacti of the United States and Canada. Stanford University Press, Stanford, California. Britton, N.L., and J. N.Rose. 1919-1923,1931. The Cactaceae. The Carnegie Institution of Washington, reprinted by the Cactus and Succulent Society of America. Brown, David. 198 Desert plants biotic communities of the American Southwest United States and Mexico. The University of Arizona for Boyce Thompson Southwestern Arboretum, Superior, Arizona., and C. H. Lowe. 1980. Biotic communities of the Southwest, Map, Rocky Mountain Forest and Range Experiment Station, United States Department of Agriculture, United States Government Printing Office, Washington, D.C. Earle, W. H. 1980. Cacti of the Southwest. Ironwood Lithographer, Inc., Scottsdale, Arizona. Ferguson, David. 198 Opuntia chisosensis (Anthony) comb. nov. Cact. & Succ. Jour. 58:124-12 Hunt, David. 198 A new review of Mammillaria names L-M. B. & R. Bradleya 3:62-6 Oxford. Solbrig, O. T., and D. J. Solbrig. 197 Introduction to population biology and evolution. AddisonWesley Publishing Co. Taylor, N. P. 198 The genus Echinocereus. The Royal Botanic Gardens, Kew, in association with Collingridge. Warnock, B. 1970. Wildflowers of the Big Bend Country, Texas. Sul Ross State University, Alpine, Texas. Wauer, Roland H. 1980. Naturalist's Big Bend. Texas A&M University Press, College Station and London. Weniger, D. 1970. Cacti of the Southwest. University of Texas Press, Austin and London. 1 Key to the Cacti of Big Bend National Park 1. Areoles bearing glochids (barbed bristles) as well as other spines; stems in a series of cylindroidal or flattened joints. Opuntia. 1. Areoles not bearing glochids; stems of various shapes Flowers and fruits (or scars) below the apex of the stem; ovary with spines Flowers and fruits (or scars) develop near the apex of the stem; ovary without spines, often with scales. Stem length 15-20 times diameter; root tuberous; 1 flowers nocturnal; ovary spines short and thick. Peniocereus greggii. Stem length usually less than 8 times diameter; root not tuberous; flower diurnal or remaining open until fading; ovary spines fine.... Echinocereus. Stems with ribs, sometimes formed by connected tubercles Stems with distinctly separate tubercles arranged in spirals Flowers appearing in early spring, species (in the park) with white to tan to light green to light pink petaloids; seeds with lateral hilum Echinomastus. Flowers appear during the spring and summer; colored other than above; hilum not as above. Ripe fruit with well-developed basal dehiscent pore, fruit wall densely covered with fimbriolate deltoid scales; flowers 6-9 cm in diameter and bright magenta, flowers appearing throughout the summer, seeds with basal hilum Theleocactus bicolor var. bolansis. Ripe fruits without well-developed basal dehiscent pore; other traits not as above Long lanceolate scales on apical portion of ovary and perianth tubes; basal dehiscence absent or poorly defined; scale of fruit and perianth with axillary wool; flowers pink to magenta Echinocactus. Scales on ovary and perianth broad and rounded, with no axillary wool visible; flowers yellow to dark rusty color Flowers yellow, fruits when ripe are light brown; radial spines thin and bristly Ferocactus hamatacanthus. Flowers dark rust colored; fruits red when ripe; radial spines not bristly Ancistrocactus uncinatus var. wrightii. Top of tubercles without groove (mature plants). Top of tubercles with groove (mature plants)... Tubercles with flower bearing portion adjacent to spine bearing portion Epithelantha. Rowers developing in axils between the tubercles. Mammillaria. Fruit mostly pale white to tan to pale pink; seeds tuberculate Fruit green to bright red; seeds not tuberculate.. 1 Tubercles triangular and hard, rough; stems flattened; spines absent Ariocarpus fissuratus. Tubercles rounded, soft and smooth; stems cylindrical to conical; spines present Neolloydia conoidea. Seed smooth with pattern of thin raised lines; flowers more than 5 cm in diameter Coryphantha. Seed pitted; flowers less than 3 cm in diameter. Escobaria. Opuntia 1. Stems round in cross section, normally with obvious elongate tubercles, young spines with papery sheaths (at least at tip) Subgenus Cylindropuntia. 1. Stems flattened, with at most slight indications of tubercles, spines without sheaths Subgenus Opuntia.

33 Subgenus Cylindropuntia 1. Stems cylindrical, much longer than wide, main branches growing upward with side branches produced radially mostly from tip joint from the previous season, spines with sheaths obvious and covering the entire spine 1. Stems club-shaped, rarely more than three times as long as wide, new joints produced mostly from near base of old joints, forming mostly prostrate branches which make up a low mat-like plant, spines with minute sheath only at tip O. schottii. Stems thick, mostly greater than 2 cm diameter; flowers large, mostly greater than 5 cm diameter; fruit strongly tuberculate, yellow when ripe O. imbricata. Stems thin, less than 2 cm diameter; flowers small, usually less than 4 cm diameter; fertile fruit not strongly tuberculate, often reddish or red Stems mostly less than 7 mm in diameter, typically with 0-1 spine per areole; flowers yellow, less than 2 cm diameter, opening in late afternoon O. leptocaulis. Stems mostly greater than 9 mm diameter, with at least 2 spines per areole (in most areoles); flowers variable in color, but mostly pink, lavender, or rust, mostly 3-4 cm diameter, opening in morning and closing in afternoon O. kleiniae. ple throughout; flower buds not acutely pointed at the apex Plants forming bushes with well formed trunks; pads bright yellowish-green with red coloring, turning yellowish and red when dormant; fruit with few stout spines mostly near the apex O. spinosibacca. Plants mostly spreading bushes without well defined trunks; pads mostly bluish-green; fruit juicy, without stout spines Spines translucent yellow (rarely orange or reddish); flowers mostly pale yellowish to buff, without bright orange or red centers; fruit with a few fine yellow spines; high elevations of the Chisos Mountains. O. chisosensis. Spines mostly opaque, white to deep reddish or blackish-brown; flowers mostly yellow with bright orange or red centers; fruit juicy, not noticeably spiny O. phaeacantha var. brunnea. Key to the Opuntia Varieties 0. imbricata 1. Arborescent, mostly 1-3 m; spines red or pink... var. imbricata. 1. Small erect shrub, mostly less than 1.2 m; spines silver var. argentea. O. Subgenus Opuntia 1. Plants forming large bushes typically with a well defined trunk; joints pubescent, spineless with prominant clusters of mostly reddish-brown glochids in areoles O. rufida. 1. Plants variable, pads not pubescent and normally with at least some spines Plants forming large bushes mostly over 1 m high with poorly defined main trunks; pads mostly greater than 20 cm long; flowers large, mostly greater than 7 cm in diameter, bright yellow with little orange or red color, however, fading to orange with age; stigma lobes dark green; fruit mostly greater than 5 cm long, umbilicus shallow, nearly flat; seedlings with fine hair-like flexible spines Plants typically forming low growing bushes under 1 m high, or with a well defined trunk; pads mostly less than 20 cm long; flowers mostly less than 7 cm in diameter, commonly with strong orange or red pigment near the base of the petals; stigma lobes white to pale green; fruit mostly less than 5 cm long, umbilicus typically strongly concave, seedlings not hairy Spines mostly translucent bright yellow, occasionally dark at base, mostly round or oval in cross section, typically longest along lower edge of pads; fruit mostly pyriform; growing in moist habitats near the Rio Grande River O. lindheimeri. Spines mostly opaque yellowish to white, normally dark reddish at base, mostly flattened in cross section, not noticeably longer along lower edge of pads; fruit mostly ovoid to globose; growing in various habitats, however, mostly dry or well drained areas. O. engelmannii. Pads usually strongly purplish, especially in drought, heat or cold; flower buds acutely pointed at the apex O. macrocentra var. macrocentra. Pads usually green, in drought or cold reddish or with red zones around the areoles, not turning pur- lindheimeri 1. Erect shrubs; stems obovate; spines in all but the lower areoles; near Boquillas Canyon Overlook so far as known var. lindheimeri. 1. Sprawling shrubs; stems elongate lanceolate; spines distributed irregularly or on some joints lacking; escaped cultivar and found along the River Road. var. linguiformis. 0. macrocentra 1. Plants with many slender spines, yellow to dark reddish-brown (nearly black) with yellow tips, spines over nearly all areoles; fruit drying soon after ripening, usually with many fine yellow spines O. macrocentra var. aureispina. 1. Plants with spines mostly deep reddish-brown to black (rarely white) with white tips, spines on upper areoles; fruit purple to red and juicy when ripe, usually with no or a few spines on the top edge of the ovary Joints typically dull dark green when not dormant, somewhat glaucus, commonly narrowed toward the base and broadest near the apex; areole counts across the middle mostly 6-8; spines tending to point mostly outward and downward except at edges of young pads; fruit mostly dull purplish, purple inside O. macrocentra var. macrocentra. Joints typically strongly bluish-green when not dormant, strongly glaucus, usually not noticeably narrowed toward the base; areole counts across the middle mostly 5-6; spines tending to point in all directions, often curved; fruit mostly pinkish-red and mostly greenish inside O. macrocentra var. minor. Echinocereus 1. Flowers orange-red, once opening remaining open day and night until fading

34 1. E. coccineus Engelm. var. gurneyi (Benson) D. Ferguson Flowers other colors, diurnal (opening in day and closing at night) Flowers green to rusty-red, not opening widely, normally 18 mm (30) in diameter.. E. russanthus. Flowers other colors, opening widely, over 50 m m in diameter Spines thin, bristly and flexible; areoles on ovary with much white wool E. chisoensis. Spines stiff; areoles on ovary naked Central spines over 25 mm long; usually 7-12 ribs; stems densely clustering from the base to form hemispherical mounds; areoles distant so spines only partially obscure the stem All spines less than 25 mm long; usually 14 or more ribs; mostly single or sparingly branched; areoles close so spines virtually obscure the stem Spines glassy, uniformly colored on the same areole, usually white to yellow or rarely pink to reddishbrown E. stramineus. Spines dull, variously colored on the same areole, tan to dark grey E. enneacanthus. Spines from adjacent ribs overlap densely covering the stem; central spines shorter than radials but longer than h the length of the radials E. dasyacanthus. Spines from adjacent ribs not overlapping or minimally, usually exposing the stem; central spines shorter than h the length of the radials E. ctenoides. Coryphantha 1. Groove only running part of the length of tubercle; stems soft and flabby; outer perianth erose; fruits purple C. macromeris. 1. Groove running full length of tubercle; stems firm; outer perianth entire; fruits green Stems depressed conical; spines tan to grey; lower central similar to upper centrals and descending; flowers pink C. ramillosa. Stems globose; spines white to tan, lower central noticeably thicker than all other spines and porrect; flowers yellow C. echinus. Mammillaria 1. Stems erect and much longer than the diameter... M. pottsii. 1. Stems low, usually much wider than height.... Spines white; stems normally 2-3 cm in diameter; fruits cylindrical; seeds black.... M. lasiacantha. Spines tan to pale brown; stems often over 5 cm in diameter; fruits clavate; seeds brown Radial spines 5-9 M. meiacantha. Radial spines 12 or more M. heyderi var. applanata. l l Echinocactus 1. Stems low and wide, ribs acute; flowers white to pink; fruits globose, thick-walled, fleshy, red E. texensis. 1. Stems upright, ribs rounded; flowers magenta; fruits elongate, thin-walled, seeds not embedded in pulp, E. horizonthalonius. pale pink Epithelantha 1. Flowers not opening widely, usually less than 4 mm in diameter, petal tips at or just above spine tips; in park at elevations over 1,060 m E. micromeris. 1. Flowers opening widely, over 6 mm in diameter, above the tips of all spines; in park below 760 m. E. bokei. Echinomastus 1. Stigma lobes white to dark pink... E. intertextus. 1. Sigma lobes green Ripe fruits not dehiscing by any regular pattern; all central spines ascending E. wamockii. Ripe fruits dehiscing vertically; main central spine porrect to descending E. mariposensis. Escobaria 1. Seeds brown; fruits with mucilaginous pulp; stigma lobes white to pink 1. Seeds black; fruits with watery pulp; stigma lobes green Flowers pink with a well defined midstripe, narrow funnel form and less than 15 m m in diameter; fruits E. albocolumnaria. green to dull red Flowers lavender with a very faint midstripe, opening widely and nearly rotate, over 18 mm in diameter; fruits red Radial spines 20-30; juvenile stems and young offsets with shaggy appearance similar to the adult stems; mostly below 900 m elevation E. tuberculosa. Radial spines 15-20; juvenile stems and young offsets with smooth appearance dissimilar to adult stems; Chisos Mountains (above 900 m elevation). E. tuberculosa var. varicolor (comb. nov.). Stems conical and usually less than 15 mm tall; fruits with deciduous perianth; often growing in limestone cracks E. duncanii. Stems globose and more than 30 mm tall; fruits with persistent perianth; usually not found growing in limestone cracks Flower petals with midstripe over half as wide as petal; growing in pinyon-juniper woodlands above 900 m elevation E. chaffeyi. Flower petals with midstripe less than half as wide as petal; growing in desert flats below 900 m elevation E. dasyacantha. SHOW CALENDAR The 22nd Biennial C.S.S.A. Convention will be hosted by the Colorado Cactus and Succulent Society, and will be held at the Executive Tower Inn in downtown Denver, from June 12 to 16, 198 Start planning now!