LESKEACEAE. 



445 



Family 10. LESKEACEAE Reichenbadi. 

 LESKEA FAMILY. 



Plants small or large; stems creeping and branching, somewhat irregu- 

 larly or regularly pinnate; branches short, usually slender and crowded 

 with small leaves; vein single, cells usually papillose on one or both sur- 

 faces; branch leaves smaller than the stem leaves, rudimentary leaves 

 present. Pedicel erect or inclined ; calyptra cucullate ; lid conic or beaked ; 

 annulus usually present; peris-tome double, inner sometimes shorter and 

 imperfect. About 23 genera containing some 333 species. 



Le.-ives papillose only on the back. 

 Leaves papillose on both surfaces. 



1. Haplocladium. 



2. Thitidiuin. 



1. HAPLOCLADIUM C. Mull. 



Branches slender, simple, not pinuately divided; leaves papillose only on 

 the back, those at base of pedicel, erect, longer and paler. [Greek, referring 

 to the simple branches.] A genus of 43 species, natives of America and 

 Eastern Asia. Type species: Haplocladium niftcropilmn C. Muell. 



1. Haplocladium microphy Hum (Sw.) 

 Broth. SMALL-LEAVED HAPLOCLADIUM. 

 (Fig. 490.) Plants slender, perennial, 

 dark green or yellow ; stems creeping and 

 rooting, sometimes quite slender and up 

 to several inches long; branches short 

 and simple, erect ; leaves crowded, spread- 

 ing or secund, ovate-acuminate ; vein ex- 

 current into a long tip; margins 

 minutely toothed; cells small, square or 

 oblong, papillose only on the back; 

 leaves at base of pedicel longer and 

 paler, erect. Seta long and slender, 

 erect ; capsule horizontal and curved ; 

 annulus falling with the conic lid; peri- 

 stome double; inner peristome with 

 keeled segments and 3 cilia ; spores 

 smooth, maturing in summer. [Hypnum 

 microphyllum Sw.] 



On rocks in shade ; not common fruit- 

 ing. Also found in various parts of the 

 United States, the West Indies and Mexico. 



2. THUIDIUM Br. & Sch. 



Plants minute or taller and much branched; stems creeping or erect; 

 branches rarely simple, more often regularly pinnate or bipinnate; leaves 

 ovate, acute or acuminate; vein single, stout, ending in or below the tip; 

 cells small, dense, papillose on both surfaces. Pedicel erect; capsule hori- 

 zontal or curved; caiyptra cucullate; lid beaked; annulus compound; peri- 

 stome double. [Diminutive of Thuja.] A large genus, widely distributed in 

 temperate regions, with some 63 species in America, the following typical. 



