b. St. bi- or tri-pinnate: dioicous.
431. H. (Thuyidium) delicatulum. L. St. elongate, erect or procumbent, bipinnate; br. drooping, often rooting at apex; l. broadly cordate or ovate-acuminate, sub-striate, papillose or muricate on back and keel, nerved nearly to apex, which is finely serrulate; caps. sub-cylindrical curved, cernuous, pale brown, lid large conical, not rostrate.
Limestone and chalk rocks, &c. VII. VIII.
432. H. (Thuyidium) tamariscinum. Hedw. St. elongate, arched, procumbent, interruptedly tri-pinnate; br. not rooting; st. l. cordate acuminate, plicate; br. l. ovate, obtuse; all papillose at back, but not so much so as last; serrulate near and nerved almost to apex; caps. oblong-cylindrical, curved, cernuous, purplish red; lid large conical, with a long beak.
Woods and banks, frequent. XI.
Sub-genus II. Ptychodium. Branches sub-pinnate; l. patent and secund, often deeply sulcate, thinly nerved to apex; areolæ shortly linear, quadrate at the angles; caps. cernuous, horizontal, ovate; per. teeth dense and narrow, lamellose, cilia rudimentary.
433. H. (Ptychodium) plicatum. Schl. St. creeping, tomentous; branches ascending incurved; l. ovate, imbricate, pointed, margin recurved; per. l. twice as large; caps. ovate-oblong, small, on a half-inch reddish seta: dioicous.
Alpine rocks. S. IV. (?)
Sub-genus III. Camptothecium. Stems trailing in part, sub-erect, branched; l. silky, striate, thinly nerved, areolæ narrowly linear; caps. cernuous, on a smooth or rough incurved seta; lid shortly rostrate or conical; internal perist. with long cilia.
434. H. (Camptothecium) lutescens. Dill. St. about 3in. irregularly branched, sometimes pinnate; l. narrowly lanceolate, tapering to a long point, entire, nerved nearly to apex; caps. oblong arcuate, on a rough seta; lid conical, beaked: monoicous.