86 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 11 



long, with three to five folds or keels above, the mouth contracted, divided into 

 six to nine triangular segments. Capsule ovoid, dark red-brown, the wall of 

 four or five layers, the outermost layer of large cells with dark thickening 

 bands, the inner layers of smaller cells with both radial and tangenital thicken- 

 ings. Elaters long, tapering, bispiral to the tips. 



Type species: Jungermannia subtrifida J. D. Hooker & T. Taylor. 



1. Triandrophyllum subtrifidum (J. D. Hooker & T. Taylor) Fulford & 

 Hatcher, Bryologist 64: 350. 1961 [1962]. 



Jwngermanmia subtrifida J. D. Hooker & T. Taylor, London Jour. Bot. 3: 579. 1844. 

 Isotachis subtrifida (Hooker & Taylor) Mitten, in J. D. Hooker, Bot. Antaret. Voy. 2 2 : 

 148. 1855. 



Isotachis ripensis Spruce, Trans. Proc. Bot. Soc. Edinb. 15: 339. 1885. 

 Isotachis anceps Massalongo, Nuovo Gior. Bot. Ital. 17: 219. pi. 15, f. 9. 1885. 

 Isotachis nordenskjoldii Stephani, Spec. Hep. 3: 659. 1909. 

 Isotachis halleana Stephani, Sv. Vet.-akad. Handl. 46 9 : 69. f. 37 a, b. 1911. 

 Isotachis lanciloba Stephani, Sv. Vet.-akad. Handl. 46 9 : 70. /. 26 f-g. 1911. 

 Isotachis heterophylla Stephani, Spec. Hep. 6: 354. 1924. 



Isotachis mutabilis Herzog in Herzog & Hosseus, Arch. Escuel. Farm. Fae. Ci. Medi 



Cordoba 7: 26. 1938. 

 Isotachis ripensis var. armata Herzog, Revue Bryol. Lichenol. 11: 24. 1938 [1939]. 



Plants of medium to large size, brown, ascending to erect, in tufts or 

 cushions ; stems to 6 cm long, with leaves to 3 mm wide, irregularly branched ; 

 lateral branches leafy, occasional, ventral branches intercalary, more frequent, 

 leafy or flagelliform ; stems in transverse section 12 to 16 cells in diameter, the 

 cells of the cortical band in one or two rows, small, thick-walled, those of the 

 medulla large, with thinner walls. Line of leaf insertion oblique and decurved 

 at the dorsal end, the leaves ineubous. Leaves approximate to imbricate, spread- 

 ing, tending to be deflexed, asymmetric, 1-2 mm long, 0.9-1.5 mm wide, ovate 

 to ovate-truncate, the margins entire, bifid or trifid to one-half of their length ; 

 segments lanceolate or broader, acute to blunt; leaf-cells at the base of the 

 segments quadrate to hexagonal in outline, 27-36 X 27-30 p., thin-walled, the tri- 

 gones minute or absent, the cuticle smooth to verruculose. Underleaves sym- 

 metric, as large as the leaves or scarcely smaller. Plants diocious. Male inflor- 

 escence terminal becoming intercalary on the stem or a branch, the bracts and 

 bracteoles in eight or more series, similar to the leaves and underleaves, the 

 margins often with more teeth ; antheridia two or three in the axils of both 

 bracts and bracteoles. Female inflorescence terminal on the stem or branch, 

 without or with one or two subfloral innovations, the bracts and bracteoles like 

 the leaves and underleaves, slightly larger, the lateral margins with a few teeth. 

 Perianth 2-3.5 cm long, fusiform, divided to one-fourth of its length into six 

 to nine entire, lanceolate lacineae. Sporophyte capsule red-brown, the Avail of 

 five layers of cells, in surface view, the outer layer with knot-like thickenings 

 in rows along the radial walls; elaters long, tapering, bispiral; spores red-brown, 

 averaging 20 p, smooth to faintly verruculose. Fig. 1, a-g. 



Habitat: Over soil and rocks in moise shaded areas in open meadows, banks. 



etc. 



GUATEMALA: San Marcos: Volean Taeana, Steyermarl 36008, 36451 (F). 



COSTA RICA: Volc.ln Tuirealla, 2000-2400 m, Standley 35279 (as I. ripensis var. 

 armata) (isotype, ITS) ; San Jos4, Las Nubes, 1500-1900 m, Standley 38361 (US). 



COLOMBIA: Huila-Cauea : Paramo de Las Papas, Bischlrr 842, 846, 848 (COL); Cauca: 

 Paramo de Las Papas, Bischler 900 (2), 903 p.p. (COL). 



