An Unusual New (-) from New STOR ® Robert J. Soreng; Richard W. Spellenberg

Systematic Botany, Vol. 9, No. 1. (Jan. - Mar., 1984), pp. 1-5.

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http: //www .j stor. org/ Thu Oct 19 16:05:47 2006 Systematic Botany (1984), 9(1): pp. 1-5 © Copyright 1984 by the American Society of Plant Taxonomists

An Unusual New Chaetopappa (Asteraceae-Astereae) from

ROBERT J. SORENG and RICHARD W. SPELLENBERG Department of Biology, New Mexico State University, Las Cruces, New Mexico 88003

ABSTRACT. Chaetopappa elegans, a narrow endemic from the White Mountains of south-central New Mexico, is unusual in Chaetopappa because of its double pappus of numerous bristles and narrow scales, comparatively long, lanceolate stylar appendages, crinkled stem pubescence, alveo- late receptacle, faint cypsela nerves, long ligules, and occurrence on granitic rock. Its chromosome number is In = 9•. In habit it resembles C. hersheyi from the nearby Guadalupe Mountains, but characteristics of the head are more like those of C. bellioides and C. pulchella from north-central Mexico and the Big Bend region of , and Leucelene ericoides, widespread in arid southwestern . In its alveolate receptacle it resembles some species of and the West Coast , whereas its double pappus is reminiscent of some species of Erigeron and Aster (sect. Ionactis). The crinkly stem hairs are like those of some Erigeron species.

A portion of the front ranges of southcentral the general composition of the vegetation wi New Mexico, the White and Sacramento moun- which they are associated. tains, form a continuous north-south oriented The new species described herein adds oi chain about 130 km long. The northern, pri- more endemic element to the White Moun- marily igneous portion, the White Mountains, tains, one that is associated with a small genus rises to about 3660 m on Sierra Blanca, the of more southern affinity. Species of Chaetopap- southernmost glaciated peak in North Ameri- pa are found in the mountains, hills, and plains ca. The southern portion of the chain, the Sac- in and surrounding the arid grassland regions ramento Mountains, are primarily limestone of the northern portion of the Mexican Plateau, and are considerably lower, barely exceeding extending onto the southern Great Plains as far 2740 m. This small mountain chain is isolated north as . This new Chaetopappa is un- from other mountain ranges in the Southwest usual in that it occurs on granitic rocks at rel- by fairly broad low gaps of arid grassland or atively high elevations, whereas its closest rel- desert, gaps that serve as barriers to migration atives all occur well to the south and then on of montane vegetation. To the north and south limestone. these gaps are relatively small and not partic- It is also unusual in a number of morpholog- ularly low (cf. map on p. 34 in Patterson 1980). ical features. Shinners (1946a) redefined Chae- During elevational fluctuation of vegetation in topappa to include a number of smaller genera the late Pleistocene (Van Devender and previously distinguished by pappus differ- Spaulding 1979) these gaps were narrowed even ences. The publication of C. plomoensis B. Turn- more and were, therefore, even less of a barrier er (Turner 1977) added a new kind of pappus to vegetation migration. On the one hand, the to the genus. Our new species, with its pappus isolation of these mountains has produced an of numerous bristles and scales, further adds to area of comparatively high endemism for New pappus types known in the genus. In addition, Mexico, while on the other the isolation has it has stylar appendages, stem hairs, and a re- not been so complete that the vegetation has ceptacle unique in Chaetopappa but similar in sharply differentiated. from the higher these characteristics to at least some species in elevations are mostly conspecific with those to Pentachaeta, Aster, and Erigeron. The faint nerves the north; plants from lower elevations find of the cypsela of C. elegans contrast to the prom- their congeners mostly to the south. Most en- inent nerves on all other Chaetopappa. demics in these mountains apparently have di- verged but slightly from ancestral stock and Chaetopappa elegans Soreng & Spellenberg, sp. show patterns of relationship similar to that of nov. (fig. 1).•TYPE: U.S.A., New Mexico, 1 SYSTEMATIC BOTANY [Volume 9

I mm 5 mm

I mm

FIG. 1. Chaetopappa elegans. A. Habit. B. Cypsela and pappus. C. Involucre. D-E. Style branches from disk and ray florets, respectively. F. Disk , portion of pappus removed. (A, C-F from Spellenberg 6478; B from Soreng et al. 2026.) 1984] SORENG & SPELLENBERG: CHAETOPAPPA

Lincoln Co., Eagle Creek Canyon, on the about 12 mm except for one or two minute NE flank of Sierra Blanca, 105°45'W, , the uppermost often closely sub- 33°25'N, T10S, R12E, E edge Sec. 26, 2500 tending the involucre. Involucre 4.5-6.5 mm m, 11 Jul 1982, R. Soreng, R. Spellenberg, and high, the phyllaries imbricate in 3-4 series, D. Ward 2026 (holotype: NY; isotypes: K, widely spreading after release of cypselas, the NMC, TEX; this collection is also the cy- outermost about half the length of the inner, tological voucher). oblong-lanceolate, acute to acuminate, erose- Plantae perennes dense caespitosae; caules fimbriate on at least the upper margins and tips, erecti vel adscendentes saepius 3-5 (sed usque only slightly arched across the back, purplish 9) cm longi 1-2-ramiferi villosi, pube infra in- to brownish, the inner ones with white scari- volucrum densiore; folia spatulata obtusa api- ous margins, at least the outer ones finely pu- culata 3-17 mm longa, 1-2.5 mm lata, interno- bescent and with stout hairs medially, less diis multo longiora ciliata, nervo 1 prominulo; commonly nearly glabrous. Receptacle slightly capitula terminalia solitaria, involucro 4-8 mm convex, up to 2 mm broad, glabrous, alveolate, alto; phyllaria imbricatis 3-4-seriatis pubescen- the point of attachment of each cypsela marked tibus, marginibus praecipue apicem versus sca- by minute knob. Ray florets 10-24, pistillate, riosa et eroso-fimbriata; ligulae 10-24 roseae vel ligules curling back in age, when fresh pale to pallide lilacinae 5-9 mm longae; flosculi dis- deep pinkish-lavender, fading to nearly white corum 15-45, 3.8-6 mm longis, in parte basalis in the field (but drying bluish in herbarium constrictis parce pubescentibus; cypsela com- specimens), 5-9 mm long, 1-2.6 mm wide; the planata 2.5-3 mm longa sericea, pappi duplicis tubular portion pale green, 2-2.5 mm long, setis interioribus capillaceis 13-19, squamis ex- sparsely pubescent with short multicellular, bi- terioribus brevissimus angustis minus nume- seriate hairs. Disk florets 15-45, corollas 3.8-5 rosis; chromosomatum numerus 2« = 9•. mm long, mostly pale yellow (often drying with Densely cespitose perennial, probably from a rosy tinge in the upper %), the lower portion a taproot, the perennating stems from the crown constricted, pale green, ca. 1 mm long, pubes- slightly woody, vertically or obliquely much- cent as in the tubes of the ray florets, the lobes forked, often subrhizomatous. Stems spreading of the limb triangular, tipped with minute or ascending, slightly sinuous, up to 9 cm long, glandular hairs. Anthers with lanceolate ter- mostly 3-5 cm high, simple or with a few minal appendages about 0.5 mm long. Style branches arising about the middle, the inter- branches of the disk florets about 1.5 mm long, nodes up to 9 mm long, much shorter than the the stigmatic lines ca. 0.8 mm long, the ap- , sparsely pubescent with crinkled, as- pendages narrowly lanceolate, from slightly cending or loosely appressed, many-celled shorter to slightly longer than the stigmatic re- hairs, the cells tending to collapse, the cross- gion, covered adaxially with long collecting walls white, prominent. Leaves somewhat thick, hairs. Style branches of the ray florets lacking oblanceolate or spatulate, obtuse to acute, the appendages. Cypselas 2-2.5 mm long, narrow- nerve prominent beneath and slightly im- ly oblanceolate, slightly compressed, about 0.4 pressed above, the tip often with a trans- mm wide and Vi-% as thick, shouldered at the lucent mucro, the margins pectinate-ciliate with top, with two faint marginal ribs (a weak third multicellular, forward-curved hairs from rib often evident on ray cypselas), sericeous mound-like bases, the hairs reduced in size to- with ascending-spreading biseriate hairs that ward the apex of the blade, both surfaces either are minutely bifid at the tip. Pappus double, of glabrous or sparsely short-pubescent; basal about 13-19 pale, tawny, scabrous bristles ap- leaves in a rosette-like cluster, mostly shorter proximately equalling the corolla tube, alter- and narrower than the cauline ones, 3-15 mm nating with an outer series of narrowly lanceo- long, 1-2 mm wide, the base expanded; cauline late or setose, minutely lacerate scales 0.5-0.8 leaves 5-25, gradually reduced upward, nearly mm long. In = 9•. equally spaced, overlapping, 5-17 mm long, 1- The specific epithet refers to the attractive 3 mm wide, the uppermost often abruptly re- heads, which are exceptionally showy for the duced. Heads solitary at the end of the stem (or genus. This new species was discovered in the the occasional branch), the stem leafy to the spring of 1981, growing on granite outcrops base of the head, or nearly naked for up to with Potentilla sierra-blancae Wooton & Rydb. SYSTEMATIC BOTANY [Volume 9 and Valeriana texana Steyerm., both rare and with its uniseriate pappus of about 25 bristles, under consideration for Federal "threatened" may serve to bridge the gap between the two or "endangered" status. We returned in 1982 genera. Chaetopappa plomoensis, however, has the to collect more material and noted that the keeled phyllaries that are characteristic of most number of rock outcrops in the canyon would Chaetopappa and rather unlike those of the oth- provide habitat for perhaps no more than a few er species referred to above. Leucelene is known thousand individuals. As far as is now known only to have x = 8 chromosomes, and to have C. elegans is restricted to granitic outcrops in short, blunt stigma appendages, characteristics this one canyon. of many species of Chaetopappa, but differing in Additional collections from the immediate these respects from ours. vicinity of the type locality: R. Soreng and L. In number of chromosomes, leaf arrange- Soreng 1589 (WAT), 1590 (LE), 22 May 1981; R. ment and form, double pappus, number and Soreng and D, Ward 1603 (ILL, UNM), 17 Jun coarseness of pappus bristles, alveolate recep- 1981; R. Spellenberg 6478 (COLO, MEM, NMC, tacles, showy , and long, lanceolate sty- UC), 23 May 1982. lar appendages, C. elegans is difficult to exclude Assigning this new species to genus gave us from Aster sect. Ionactis (Semple and Brouillet some difficulty. Even though this new species 1980) or Aster subg. Ianthe (Jones 1980). How- has an imbricate involucre and we considered ever, habit, absence of rhizomes, reduced inflo- Chaetopappa to be its proper affiliation, our first rescence, nature of the chlorophyllous zone of inclination, based primarily on the double pap- the phyllaries, and the absence of fine scabrous pus of a fairly large number of bristles and the pubescence would make the new species multicellular, crinkly stem hairs, was that we anomalous in either group of asters. We there- had discovered a species of Erigeron. The ces- fore return to the heterogeneous Chaetopappa. pitose, rock-inhabiting nature of the species, In Chaetopappa this new species is most sim- the multicellular trichomes with cells that col- ilar in habit to the geographically adjacent lapse at right angles to one another, and the chasmophile C. hersheyi S. F. Blake from the chromosome number of n = 9 also are charac- Guadalupe Mountains of Texas and New Mex- teristic of many erigerons. However, Dr. Guy ico. Shinners (1946a) placed C. hersheyi in the Nesom examined our material and excluded it monotypic sect. Hersheyanae. Van Horn (1973) from that genus because of its linear-lanceolate also reviewed a number of features of C. her- stylar appendages with long, flexuous collect- sheyi that differ from other members of the ge- ing hairs, the comparatively low number of disk nus. Chaetopappa hersheyi also has comparative- flowers per head, and the microscopic, glan- ly long, pointed stylar appendages, although dular, biseriate trichomes on the cypsela sur- they are proportionally shorter than in C. ele- face. gans. However, C. hersheyi strongly differs in its In its phyllaries and the number of pappus smaller heads with glabrous, keeled phyllaries, bristles (13-19) C. elegans resembles the mono- its more numerous nerves on the cypsela, its typic Leucelene (usually 25 bristles), a genus reduced pappus of few setae and scales, and in Shinners (1946b), G. Nesom, and B. L. Turner its having hirsute stems. (pers. comms.) have noted to be closely allied In several significant respects C. elegans ex- with Chaetopappa, if not congeneric with it. hibits stronger affinity with C. bellioides and C. Phyllaries of C. bellioides (A. Gray) Shinn. and pulchella, and we tentatively ally the new species C. pulchella Shinn. are strikingly similar to the with these in the series Bellioideae (Shinners aforementioned two species. However, Chae- (1946a), noting it may warrant its own mono- topappa species known prior to 1977 differ in typic series. These three species, as noted above, having, among other characters, a low number have similar phyllaries, two nerves on the cyp- (0-6, exceptionally to 9 in C. pulchella and C. sela, acute stylar appendages, and comparative- bellioides) of relatively short stout pappus bris- ly large heads. In addition, C. pulchella and C. tles or awns, with an outer series of squamel- bellioides occasionally exhibit weakly alveolate lae, or have no pappus at all. Our new species, receptacles. In Correll and Johnston (1970) and which also has an outer series of scales, and the in Shinners (1946a) C. elegans "keys" under the recently described C. plomoensis (Turner 1977) first lead "involucres campanulate or hemi- 1984] SORENG & SPELLENBERG: CHAETOPAPPA spherical in flower .. .," placing the species LITERATURE CITED near C. bellioides and C. pulchella, although in C. CORRELL, D. S. and M. C. JOHNSTON. 1970. Manual elegans the heads sometimes have too few flow- of the vascular plants of Texas. Renner: Texas Re- ers to meet all the requirements of this lead. It search Foundation. is immediately distinguished from these species FEDOROV, A. A., ed. 1969. Chromosome numbers of by its cespitose habit, long rays, crinkly pe- flowering plants. Acad. Sci. USSR, Komarov Botan- duncle hairs, and its pappus of many bristles ical Institute. and scales. and C. pulchella JONES, A. J. 1980. A classification of the New World also have reported chromosome numbers of species of Aster (Asteraceae). Brittonia 32:230-239. both 2« = 8 or 9 pairs, although 8 is more fre- MOORE, R. J., ed. 1977. Index to plant chromosome quent (Fedorov 1969; Moore 1977, where the numbers for 1973/74. Regnum Veg. 96. PATTERSON, B. D. 1980. Montane mammalian bio- count for C. bellioides reported as n = 9 has been geography in New Mexico. Southw. Naturalist changed on the voucher specimen to n = 8 by 25:33-40. B. L. Turner, the specimen annotated by D. Pin- SEMPLE, J. C. and L. BROUILLET. 1980. A synopsis of kava, and also Turner, to C. pulchella). Other North American asters: The subgenera, sections than in these two species n = 9 is known in and subsections of Aster and Lasallea. Amer. J. Chaetopappa only from our new species and Bot. 67:1010-1026. from the rather dissimilar C. effusa (A. Gray) SHINNERS, L. H. 1946a. Revision of the genus Chae- Shinn. topappa DC. Wrightia 1:63-81. . 1946b. Revision of the genus Leucelene ACKNOWLEDGMENTS. We thank Guy Nesom for Greene. Wrightia 1:82-85. invaluable help concerning the boundaries of Erig- TURNER, B. L. 1977. A new species of Chaetopappa eron, B. L. Turner for valuable comments on the (Asteraceae-Astereae) from north-central Mexi- manuscript, Darrell Ward for the chromosome count co. Sida 7:22-23. he made on the new taxon, and Rupert C. Barneby VAN DEVENDER, T. R. and W. G SPAULDING. 1979. for help with the Latin description. Development of vegetation and climate in the southwestern United States. Science 204:701-710. VAN HORN, G. S. 1973. The taxonomic status of Pen- tachaeta and Chaetopappa, with a revision of Pen- tachaeta. Univ. Calif. Publ. Bot. 65:1-41.