Diplazium werckleanum Christ

Authority

Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.

Family

Athyriaceae

Scientific Name

Diplazium werckleanum Christ

Description

Species Description - Rhizomes erect, stout; rhizome scales black, lustrous, heavily indurate, ovate-lanceolate, 2–4 x 1–1.5 mm, entire; fronds 30–75(–100) cm long; stipes dark at bases, light brown or stramineous distally, 10–18 cm x 1.5–3(–4) mm, 1/2–1/3 the frond length, glabrous except for blackish scales at bases; blades thickherbaceous to subcoriaceous, 1-pinnate, 15–40 x 8–20 cm, lanceolate to narrowly deltate, apices pinnatifid, lacking buds or occasionally each blade with a bud in the axil of a distal pinna; rachises stramineous to brownish, glabrous; pinnae stalked 2–4 mm, inequilateral, mostly 5–10 pairs per blade, 9–12 x 1.5–2.5(– 3.5) cm, lanceate, bases cuneate or excised basiscopically, truncate or slightly auriculate acroscopically, apices acuminate, margins undulate and serrulate to shallowly lobed 1/4 the distance to costae; veins free, pinnate, 3–6 branches per main lateral vein, all curving abruptly toward pinna margins; indument adaxially of sparse, papillate hairs less than 0.1 mm long in rachial and costal grooves, abaxially the blades glabrous; sori often confined to first acroscopic branch of a vein group, with indusia 3–11 x 0.3–0.5 mm, erose.

Discussion

Type. Costa Rica. Werckle´ 81 (P?; frag. US!).

The D. werckleanum group (including D. cristatum and D. lonchophyllum) is taxonomically problematic in southern Mexico and Guatemala. These three species differ from each other in the degree of cutting of the proximal pinnae: in D. werckleanum the proximal pinnae are undulate to shallowly lobed 1/4 the distance to costae; in D. cristatum the proximal pinnae are deeply lobed without distinct pinnules and cut 1/2–3/4 the distance to costae; in D. lonchophyllum and D. drepanolobium (q.v.) the proximal pinnae have free basal pinnules that are merely serrate. There appear to be slight differences in indusial width and margins as well as rhizome scale width and length, but monographic work is necessary to determine if these differences are significant. Diplazium werckleanum may hybridize with D. lonchophyllum in Chiapas and perhaps other areas of sympatry; one such putative hybrid, having malformed spores, is Breedlove 22332 (MO).

Unplaced Names Diplazium anthraxacolepis Fe´e, Me´m. Foug. 8: 84. 1857. Syntypes. Mexico. Veracruz: Huatusco, Schaffner 267b, 627a (RB). Diplazium feei Schaffner ex Fe´e, Me´m. Foug. 8: 85. 1857. Type. Mexico. Veracruz: barrancas de San Marti´n et de San Francisco, 2500 m, 1854, Schaffner 265 (RB, as cited by Windisch, Amer. Fern J. 72: 58. 1982). Schaffner s.n. (P!), bearing this name, is 2-pinnate and a little more, but less divided than D. expansum and glabrous abaxially.

Excluded Species Diplazium falcatum Liebm., Mexic. Bregn. 253 (reprint 101). 1849, hom. illeg., non D. Don, 1825. Type. Mexico. Oaxaca: Teo talcingo, Chinantla, Liebmann s.n. [Pl. Mex. 2375, Fl. Mex. 361] (C!). Maxon, in 1929, annotated this specimen as “young Hemitelia sp.” We agree that it is Cyatheaceae, but cannot say what species it might be. Diplazium pectinatum (Fe´e) C. Chr. in Urban, Symb. Antill. 9: 324. 1925. Hypochlamys pectinata Fe´e, Me´m. Foug. 5: 200, t. 17C, f. 2. 1852. Type. Hispaniola. de Tussac s.n. (P?). Diplazium pectinatum (synonym Allantodia costalis Desv.) was included in the index for pteridophytes from Oaxaca (Mickel & Beitel, 1988: 551), but there is no mention of this species on the page cited (p. 159). It is closely related to D. lindbergii, but differs by the more deeply incised pinnae, with segments cut nearly to the costae, thinner blade texture, and segments spreading at a right angle to the costae. We find no other mention of the species having been recorded from Mexico or Central America. Diplazium pectinatum is confined to Jamaica and Hispaniola (Proctor, 1985), as generally construed. Diplazium prominulum Maxon, Contr. U.S. Natl. Herb. 13: 15. 1909. Type. Guatemala. Baja Verapaz. Between Purulha´ and Panza´l, Tu¨rckheim II.1683 (US; isotype P!). Diplazium prominulum was cited from Chiapas (Smith, 1981; Smith in Breedlove 1986) on the basis of Breedlove 33658 (DS). Adams (in Davidse et al., 1995) redetermined this specimen as D. lonchophyllum, and we agree. The distribution of the species as currently known is Guat, Nic, CR, Pan; Ec (Stolze et al., 1994). Diplazium prominulum is similar to D. cristatum and D. lonchophyllum except: rhizomes erect, apices lacking scales; rachises yellowish, flexuous; blades subcoriaceous; segments rounded at tips, soriferous throughout their length; and veins free, prominent abaxially. Diplazium villosum C. Presl, Suppl. Tent. Pterid. 114. 1836. The type was said by Presl to be from Mexico (Haenke s.n., probable isotypes BM!, K!, frag. NY!). This is not a Diplazium, but a juvenile specimen of a species of Cyatheaceae, probably Sphaeropteris, possibly S. integra (J. Sm.) R. M. Tryon, from the Philippines.

Distribution

Terrestrial in montane rain forests; 550–2700 m. Mexico; Guat, Bel, Hond, Salv, Nic, CR, Pan; Col.

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