HYPNACEAE. 497 



apiculate; calyptra cucullate; peristome double. [Greek, referring to the sym- 

 metric leaves.] A genus of 168 species, mostly American, in temperate and 

 tropical regions. Type species: Isopterygium planissimum Mitt. 



1. Isopterygium micans (Sw.) Cardot, Bull. Herb. Boiss. 4: 10. 1896. 

 Hypnum micans Sw. Adnot. Bot. 175. 1829. 



Plants growing in dense, glossy, yellowish-green mats. Stems slender, 

 decumbent; branches simple or divided; leaves crowded, spreading, small, 0.85 

 mm. long by 0.25 mm. wide, ovate, acuminate, faintly serrate; veins short, 

 double, obscure; cells 10 to 15 times longer than wide, a few at basal angles 

 distinctly shorter and broader. Pedicel erect, slender, up to 1 cm. long; cap- 

 sule horizontal, curved, contracted below the mouth when dry, about 1 mm. 

 long; lid conic, slightly apiculate; cilia more or less developed; spores small. 



On roots of palms and rotten wood in coppices, New Providence, Great Bahama 

 and Abaco : United States; Bermuda; Cuba; Jamaica. GLOSSY ISOPTERYGIUM. 



3. VESICULARIA C. Muell. Flora 82: 467. 1896. 

 [HOMALIA Section VESICULAEIA C. Muell. Syn. 2: 233. 1851.] 



Plants growing in moist shady places, forming thin mats on the ground. 

 Stems creeping; branches irregularly pinnate, usually short; leaves not 

 crowded, shrunken and twisted when dry, usually flattened and of two kinds, 

 the lateral ones larger and unequal, or falcate, the upper and lower ones more 

 regular and much narrower, often longer and more acuminate ; veins two, short 

 or none; margins often bordered, entire or serrate; cells large and hexagonal, 

 smooth, the alar not enlarged. Autoicous. Pedicels exserted and slender; cap- 

 sules horizontal or nodding, ovoid and contracted below the mouth when dry; 

 annulus present; peristome double; lid flat and beaked; calyptra cucullate; 

 spores small. About ninety species have been described, many with very ob- 

 scure and minute differences. [Named in reference to the large leaf -cells.] 

 Type species : Hookeria Meyeniana Hampe. 



1. Vesicularia vesicularis (Schwaegr.) Broth. Pflf. 232-233: 1004. 1908. 

 Hypnum vesiculare Schwaegr. Supp. 2 2 : 167, pi. 199. 1827. 



Plants pale or yellowish green. Stems slender and rooting with short ir- 

 regular branches; stem-leaves with long recurved tips up to 1 mm. long, about 

 three times longer than broad; branch-leaves of two kinds, the lateral unsym- 

 metric, shorter and less acuminate, up to 0.85 mm. and only about twice longer 

 than broad with the cells about twice as long as wide ; the upper and lower ones 

 longer and narrower, with cells about five times longer than broad; leaves all 

 ecostate or faintly bicostate, the margins bordered by one row of narrow cells, 

 either entire or minutely toothed at apex; perichaetial leaves suddenly con- 

 tracted to a slender recurved, entire or serrulate tip. Autoicous. Pedicel 

 slender, 1.5-2 cm. long; capsule nodding, 1-1.5 mm., ovoid, with a distinct 

 neck ; walls of swollen inflated cells ; lid conic-beaked ; annulus large ; peristome 

 with a red base, teeth yellow, pale and papillose at apex, lamellate on the in- 

 side; endostome brown, the keeled segments split and papillose; spores small, 

 ripe in winter. 



On branches and roots of trees in coppices and in sink-holes, New Providence, 

 Eleuthera and Andros : Florida ; West Indies and South America. VESICULARIA. 



