724 JUNGERMANNIACE^E. (SCALE-MOSSES.) 



five times as long as broad. (Steetzia Lyellii, Lehm.) Among mosses in 

 swamps and on dripping rocks ; common, especially southward. (Eu.) 



30. BLASIA, Micheli, (PI. 23.) 



Thallus simple or forked or stellate, with sinuous margins. Dioecious. 

 Fruit from an oval cavity in the costa. Involucre mostly none. Calyptra 

 obovate. Capsule oval-globose. Antheridia immersed in the thallus, covered 

 with dentate scales. Gemmae globose, issuing by a slender ascending tube 

 from large flask-shaped receptacles which are immersed in the thallus. 

 (Named for Blasius Biagi, a monk of Valombrosa and companion of Micheli.) 



1. B. pusilla, L. Thallus f-H' long, 2-3" wide, narrowly obovate, 

 the margins pinnatifid-sinuous. Wet banks ; common. (Eu.) 



31. PEL LI A, Raddi. (PI. 23.) 



Thallus with a broad indeterminate costa. Monoecious or dioecious. Fruc- 

 tification dorsal near the end of the thallus. Involucre short, cup-shaped, 

 lacerate-dentate. Calyptra membranous, oval, longer or shorter than the in- 

 volucre. Capsule globose. Elaters long, free. Antheridia globose, immersed 

 in the costa. (Named for A. L. Petti, an Italian botanist.) 



* Moncecious. 



1. P. epiph^lla, Raddi. (PI. 23.) Thallus oblong, lobed and sinuate, 

 somewhat fleshy, much thickened in the middle ; capsule exserted. On the 

 ground in wet places ; not uncommon eastward. (Eu.) 



* * Dioecious. 



2. P. endivisef 61ia, Dumort. Thallus flat, green or purplish, broadly 

 linear, dichotomous, the margin mostly undulate or crisped. On the ground 

 and in ditches; common, but often confused with n. 1. (Eu.) 



3. P. calycina, Nees. Thallus dichotomous, proliferous, the early di- 

 visions linear-oblong, the margins ascending and remotely sinuate, the later 

 divisions linear-palmatifid, coarsely nerved ; cells large, hexagonal ; involucre 

 ciliate-f ringed or lacerate : calyptra smooth, included. Wet limestones and 

 shales. (Eu.) 



32. METZGERIA, Raddi. (PI. 23.) 



Thallus linear, dichotomous, with well defined costa. Dioecious. Frnctifi. 

 cation arising from the under side of the costa. Involucre 1 -leaved, scale-like, 

 at length ventricose. Calyptra clavate or pyriform, fleshy. Capsule short- 

 pedicelled. Elaters unispiral, some remaining attached to the tips of the 

 valves. Spores minute, mostly smooth. Antheridia globose, enclosed in a 

 scale on the under surface of the costa. (Named for J. Metzger, a German 

 botanist.) 



* Densely villous throughout. 



1. M. pub6scens, Raddi. Thallus 1 - 2' long, 1" wide, alternately pin- 

 nate or somewhat decompound, the short linear branches of uniform width, 

 flat, the margin undulate ; hairs longer beneath, single or in twos and threes 

 near the margin, irregularly curved ; midrib nearly without cortical layer, 

 with 6-10 (mostly 8) rows of very uniform peripheral cells; dioecious. In 

 mountain regions, eastward. (Eu.) 



