PHYSCOMTTRIUM IMMERSUM, Sulliv.
Tab. 56.
Plantæ humiles, annuæ, gregariæ vel caespitulos laxos læte virides efformantes.
Caulis 2–4 lineas altns, simplex vel innovando-ramosus, inferne radiculis copiose instructus.
Folia majuscula, mollia, obovato-vel lingulato-lanceolata, acuminata, e medio ad apicem serrata; costa percurrente; reti laxo amplo, cellulis superioribus oblongo-hexagonis, inferioribus majoribus oblongis, marginalibus plus minus luteolis.
Flores monoici: flos masculus in caule juniore terminalis, tandem innovatione fertili sub eo egrediente ad latus dejectus; paraphysibus apice maxime inflatis.
Capsula immersa, subglobosa, operculo magno alte convexo-apiculato delapso hemisphærica, collo indistincto; pedicello brevissimo; calyptra erecta longirostra basi subquadriloba vix ad operculi medium descendente.
Physcomitrium immersum, Sulliv. in Gray, Man. Bot. ed. 1, 1848; Mosses U. States, p. 51, t. 4; Musc. Cubenses, No. 7.
Physcomitrium sphæricum var. ? Sulliv. Musc. Alleghan. No. 196.
Hab. River banks, Southern Ohio, Lea. Western Pennsylvania, Lesquereux. Island of Cuba, Wright. South Carolina, Ravenel.
The nearly allied Physcomitrium sphcericum has an exserted capsule, with a distinct collum, a larger calyptra, and a smaller operculum, as well as muticous leaves with nearly entire margins.
In size and external appearance Physcomitrium immersum approaches very closely the next species, Aphanorhegma serratum,
