7. DUMORTIÈRA, Nees. ([Pl. 22.])
Thallus large, thin, soft, with a slight costa, dichotomous, usually with scattered hair-like rootlets beneath; gemmæ none. Receptacle convex, 2–8-lobed. Involucres 1-fruited, connate with the lobes beneath, horizontal, opening by a vertical terminal slit. Capsule distinctly pedicelled, oblong-globose, dehiscing by 4–6 irregular valves. Elaters 2–3-spiral, parietal, very long, straight, attenuate both ways. Spores muriculate. Antheridia in a short peduncled disk paleaceous beneath. (Named for B. C. Dumortier, a Belgian botanist.)
1. D. hirsùta, Nees. Thallus 2–5´ long, 6–9´´ wide, deep green, becoming blackish, entire on the margins, naked above or with a delicate appressed pubescence; diœcious; receptacle many-fruited, the margin closely hairy; peduncle rather long, chaffy at the apex.—On moist calcareous rocks, Easton, Penn. (Porter), and southward.
8. LUNULÀRIA, Micheli. ([Pl. 25.])
Thallus oblong with rounded lobes, distinctly areolate and porose, with imbricate sublunate scales beneath; gemmæ in crescent-shaped receptacles. Diœcious. Fertile receptacle usually cruciately divided into 4 horizontal segments or involucres, which are tubular, vertically bilabiate and 1-fruited. Calyptra included, persistent. Capsule exserted, 4–8-valved. Elaters short, very slender, mostly free. Spores nearly smooth. Antheridia borne in the apical sinus of the thallus. (Name from lunula, a little moon.)
L. vulgàris, Raddi. Thallus 1–2´ long, forked, innovating from the apex, with a somewhat diffuse costa; peduncle very hairy, 1–1½´ long.—Introduced into greenhouses; always sterile, but easily recognized by the characteristic receptacles. (L. cruciata, Dumort.) (Int. from Eu.)
Order 140. RICCIÀCEÆ.
Plant-body a dichotomously branching thallus, terrestrial or aquatic. Capsules short-pedicelled, or sessile on the thallus, or immersed in its substance, free or connate with the calyptra, globose, at length rupturing irregularly. Calyptra crowned with a more or less deciduous point. Elaters none. Spores usually angular, reticulate or muriculate. Antheridia ovate, immersed in the thallus in flask-shaped cavities with protruding orifices (ostioles).
1. Riccia. Capsule immersed in the thallus. Involucre none.
2. Sphærocarpus. Capsule sessile on the thallus. Involucre inflated-pyriform.