LESKEACEAE. 



445 



Family 10. LESKEACEAE Reiclienbaeb. 



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; peristome double, inner sometimes shorter and 

 imperfect. About 23 genera containing some 333 species. 



Leaves papillose only on the back. 1. HaplorJadimn. 



Leaves papillose on both surfaces. 2. ThuiUium. 



1. HAPLOCIiADIUM C. Miill. 

 Branches slender, simple, not pinnately 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 macropiJum C. Muell. 



1. Haplocladiummicrophyllum (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. [Hypniim 

 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 ; calyptra 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. 



