68 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



I VOL. 11 



leaves and underleaves, larger, the bracts long, oval, the margins entire, bifid 

 to one-third of their length, the bracteoles more deeply cut, the segments lance- 

 olate. Perigynium 4-5 mm long, straight to slightly arcuate. Male inflorescence 

 and sporophyte not seen. Fig. 3, a-e. 



Habitat: On soil. 



PUEETO RICO: A juntas, Pagan 135 (NY). 



GUADELOUPE: Rouge River, Husnot 231b (BM, FH); s.l., I'Herminier (BM) ; s.l., 

 Marie (BM). 



DOMINICA: Roseau Valley, Elliott (BM) ; s.l., Elliott 1145, type of 1. subtruncata 

 (G), Elliott 1172 (G); s.l., Elliott 1798 (BM) ; Grand Soufriere, Elliott 872 (BM) ; s.l., 

 Eggers (NY). 



MARTINIQUE: s.l., Le Jolis (BM) ; s.l., Perrottet (BM). 



ST. VINCENT: s.l., without collector's name, (type ex Hb. Lelimann, NY); s.l., ex 

 Hb. Meissner (G). 



BARBADOS: s.l., without collector's name, ex Hb. Mitten (NY). 



The species has been reported in the literature from the following additional localities: 

 Antilles (Bescherelle, 1893; Stephani, 1901d), Puerto Rico and Guadeloupe (Pagan, 1939, 

 1942; Stephani, 1904) and Dominica (Pearson, 1922; Spruce, 1895). 



4. Isotachis madida (Hooker f. & T. Taylor) Mitten in J. D. Hooker, Bot. 

 Antarctic Voy. 2(2) : 149. 1855. 



Jungermannia, madida Hooker f. & T. Taylor, London Jour. Bot. 3: 405. 1844. 

 Isotachis fusca Stephani, Sv. Vet.-akad. Handl. 469; 68. /. 25, d-e. 1911. 

 Isotachis pollens Stephani, Sv. Vet.-akad. Handl. 46»: 70. /. 25, h-l. 1911. 

 Isotachis striolata Stephani, Sv. Vet.-akad. Handl. 46 9 : 71. /. 27, c-d. 1911. 

 Isotachis aequifoliata Stephani, Spec. Hep. 6: 349. 1924. 

 Isotachis flavicans Stephani, Spec. Hep. 6: 351. 1924. 



Plants large, pale green to greenish-brown, prostrate to ascending, in tufts 

 or mats; stems robust, 3-8 cm long, with leaves 2—3 mm wide, irregularly 

 branched ; stems in transverse section 14-16 cells across, the cortical cells in one 

 or two layers, with very thick walls. Rhizoids not seen. Leaves imbricate, spread- 

 ing, asymmetric, ovate, bifid to one-third or one-half of their length, the seg- 

 ments acute, triangular from a broad base, the sinus V-shaped ; leaf margins 

 entire or sparingly dentate in the upper half, rarely also denticulate ; cells of 

 the median portion of the leaf 60-90 X 20-30 /*, the walls uniformly thickened, 



Fig. 1. Isotachis tenax. 1 a. Stem, ventral view, X 50. 1 b. Leaf, X 4.0. 1 c. Cells 

 from the median portion of the leaf, X 350. 1 d. Underleaf, X 50. 1 e. Portion of a trans- 

 verse section of a stem, X 350. 



Fig. 2. I. multiceps. 2 a. Stem, lateral view, X 20. 2 b. Leaf, X 40. 2 c. Cell from 

 the median portion of a leaf, X 350. 2 d. Underleaf, X 40. 



Fig. 3. I. erythrorhiza. 3 a. Leafy stem with a mature perigynium, X 20. 3 b. Leaf, 

 X 40. 3 c. Cells from the median portion of a leaf, X 180. 3 d. Underleaf, X 40. 3 e. 

 Cell from the median portion of a leaf of another plant, X 250. 



Fig. 4. L. madida. 4 a. Stem, dorsal view, X 9. 4 b. Leaf, X 18. 4 c. Cells from 

 the median portion of a leaf, X 165. 4 d. Underleaf, X 18. 4 e. Female bract, X 18. 



Fig. 5. I. serrulata. 5 a. Leafy stem with a mature perigynium, X 9. 5 b. Leaf, X 18. 

 5 c. Cell from the median portion of a leaf, X 165. 5 d. Underleaf, X 18. 5 c. Leaf in- 

 sertion on the stem, lateral view. 



Fig. 6. 1. haematodes. 6 a. Stem, ventral view, X 9. 6 b. Leaf, X 18. 6 c. Cell from 

 the median portion of a leaf, X 165. 6 d. Underleaf, X 18. 



Drawn after Hatcher, 1961. 



