Brittonia, 32(4), 1980, pp. 502-504. 1980, by the New York Botanical Garden, Bronx, NY 10458

CHEILANTHES MICKELII (ADIANTACEAE), A NEW SPECIES FROM SOUTHERN MEXICO

TIMOTHY REEVES

Reeves, Timothy (New York Botanical Garden, Bronx, NY 10458). Chei- lanthes mickelii (Adiantaceae), a new species from southern Mexico. Brittonia 32: 502-504. 1980.---Cheilanthes miekelii from Oaxaca and Chiapas, Mexico is described, illustrated and compared with an apparent near relative, C. tryonii T. Reeves nora. nov.

Cheilanthes mickelii T. Reeves, sp. nov. (Figs. 1-5)

A C. tryonii T. Reeves stipite sulcato vel piano, rhachidi sulcato, squamis stipitis rhacbidumque pdmariorum necnon pinnarum integris, trichomatibus laminarum simplicibus differt.

Rhizome slender, ca 1.5 mm diameter, short-creeping, sometimes branched, at least the apices ascending; rhizome scales linear-subulate, ca 2 mm long, bicol- ored with broad, opaque, sclerotic, dark brown median stripe and very narrow, translucent, hyaline, light brown, entire margins; scale apex slender, elongate, fragile, cells with rather conspicuous reddish crosswalls. Fronds (measurements are from well developed fertile fronds; smaller fronds are frequent) 9-22 cm long; paired, crowded along rhizome, bases arcuate-ascending. Stipe 0.4-0.6 as long as blade, shallowly sulcate or flattened on upper surface, dark castaneous, lus- trous, densely covered (at least when young) with light brown, linear to filiform (hair-like) scales, some with irregular, narrow, dark median stripe, the smaller ones laxly curved, some scales with delicate tips bearing a terminal reddish "'gland" (this perhaps composed of cell wall material). Vernation non-circinate (developing frond forms a hook, not a coil). Blade elliptic or lance-elliptic, some- what narrowed at base, gradually tapered to apex, 8.5-16.0 cm long, 2.5-7.0 cm wide, thick-herbaceous, bipinnate to mostly bipinnate-pinnatifid to ca tripinnate; pinnae lanceolate, spreading or ascending, opposite or alternate, ca 9-15 pairs, lower 1 to 2 pairs somewhat reduced, median pinnae ca 2.5-4.0 cm long, 0.7-1.7 cm wide, with 5-8 pairs of pinnules, terminal "segment" elongate, acute to ob- tuse; pinnules ovate, oblong, or inequilaterally auriculate at distal base, subentire, auricu|ate, pinnatifid or pinnate, 5-10 mm long, 2-6 mm wide, mostly short pe- tiolulate; upper surface of segments dark green, moderately (when young) to sparsely pubescent with simple (unbranched), filiform, hair-like, light brown, lax- ly curved scales; lower surface light green, densely (when young) to moderately pubescent with similar scales, the leaf tissue not obscured; crosswails of the hair- like scales with '~tongue-in-groove" arrangement, these conspicuous and reddish. Indusial margin of segments somewhat modifed, whitened or translucent, be- coming more so near edge, somewhat revolute but spreading at maturity, entire, continuous on segments or lobes. Spores 64 per sporangium, globose, trilete, with rugulose perispore, 33.0-39.0 tzm in diameter with ~ = 35.5 #m (10 spores measured in lactic acid at 1000• Mickel 4210).

TYPE: MEXICO. OAXACA: Dto. Yautepec. 64 km W of Tehuantepec on Rte. 190, partially shaded, very dry, rocky slopes and dry stream bed, 2300 ft, 20 Oct 1969, Mickel 4210 (HOLOTYPE: NY; ISOTYPES: to be distributed).

PA~TYPES: MEXICO. OAXACA: Dto. Juquila: 9-25 km N of Puerto Escondido, roadbanks and woods along streams, 350-700 ft, 10 Aug 1971, Micke16068 (NY; and to be distributed). Dto. Pochutla: 4-11 km S of Pochutla on road to Puerto Angel, dry, rocky roadbanks and stream banks, 200-400 ft, 30 Sep 1970, Mickel 5194 (NY; and to be distributed). CH[APAS: Municipio of Cintalapa: slope with Quercus, tropical deciduous forest 5 km W of Rizo de Oro, 900 m, 26 Aug 1974, Breedlove 36744

1980] REEVES: CHEILANTHES 503

FI~s. I-5. Cheilanthes mickelii T. Reeves. 1. Habit. 2. Median pinna, lower surface. 3. Pinnule, lower surface. 4. Pinnule, upper surface. 5. Apex of hair-like scale from rachis showing "'tongue-in- groove" crosswalls between adjacent cells and terminal reddish "'gland." (All from Mickel 4210, NY.)

504 BRITTONIA [VOL. 32

(DS). Municipio of Arriaga: steep slopes with tropical deciduous forest along ravines 13 km N of Arriaga along Mex Hwy 195,830 m, 23 Dec 1972, Breedlove 30592 (DS).

This species is named for Dr. John T. Mickel, an authority on Mexican ferns, who collected the Oaxaca material and generously brought it to my attention. Cheilanthes mickelii is similar in several respects to the species formerly known as Notholaena cinnamomea Baker (see R. Tryon, 1956). I follow Tryon and Tryon (1980) in treating the first 21 species covered in R. Tryon's 1956 treatment of Notholaena as belonging to Cheilanthes. The resulting circumscriptions of the genera Cheilanthes and Notholaena seem improved over previous ones but the long-standing debate over the status of Notholaena dictates continued study (see M~ckel, 1979). I here make the new name necessary in Cheilanthes for Notho- laena cinnamomea:

Cheilanthes tryonii T. Reeves, nom. nov.

Notholaena cinnamomea Baker in Hooker & Baker, Syn. Fil. ed. 2. 515. 1874. Cheilanthes cin- namomea Domin, Bibl. Bot. 20 (Heft 85): 133. 1913; not Ch. cinnamomea D. C. Eaton in A. A. Eaton, Proc. Amer. Acad. 18: 186. 1883. TYPE: GUATEMALA: Motagua ("Montagua" fide R. Tryon, 1956), in 1862, Salvin & Godman s.n. (K, not seen, photo GH!). Other material examined: GUATEMALA: Volcfin de Fuego, O. Sah, in s.n. (GH!).

This new name honors Dr. Rolla M. Tryon who has written many excellent treatments of cheilanthoid ferns in particular and New World ferns in general.

Cheilanthes mickelii resembles C. o~yonii in general appearance, in shape, size and degree of dissection of the blade, in the moderate degree of modification of the indusial margin of the segments, in the slender, short-creeping rhizomes and bicolored rhizome scales, and in the presence of narrow scales on the stipe, rachis and blade. These narrow scales are predominantly hair-like and some have del- icate apices with a terminal reddish ~glandular" tip. Cheilanthes mickelii differs from C. tt3,onii in its sulcate or flattened stipe and sulcate (rather than terete) rachis, in the entire (rather than long-dentate) scales on the stipe, rachis and pinnae rachises, and in the simple (rather than branched) hair-like scales on the surface of the segments. The indument of C. mickelii is also less dense than in C. tryonii. The affinities of these species appear to be with the group which includes among others C. microphylla (Sw.) Sw., C. alabamensis (Buckl.) Kunze, and C. cucullans F6e.

Acknowledgments

I wish to thank Dr. Mickel for suggesting critical evaluation of this material and Dr. A. Reid Smith for providing the Chiapas collections for study. I also thank Drs. R. M. and A. F. Tryon for kindnesses extended during my visit to the Gray Herbarium. My wife, Linda, prepared the illustrations.

Literature Cited

Mickel, J. T. 1979. The fern genus Cheilanthes in continental United States. Phytologia 41: 431- 437.

Tryon, R. 1956. A revision of the American species of Notholaena. Contr. Gray Herb. 179: 1-106. - - & A. Tryon. 1980. Proposals to conserve or reject. (517) Proposal to conserve Notholaena

with the type Pteris trichomanoides. Taxon 29: 160-161.