Pseudocrossidium pachygastrellum (Herzog) Broth., (Argentina). In: L. Ellis, ed. New national and regional bryological records

GUILLERMO M. SUÁREZ & MARÍA M. SCHIAVONE

JOURNAL OF BRYOLOGY

MANEY PUBLISHING

Lugar: Inglaterra; Año: 2010 vol. 32 p. 311 - 322

0373-6687

During examination of collections from “La Cienaga”, in the Northwest of Argentina, certain specimens were identified as Pseudocrossidium pachygastrellum, a species of Pottiaceae recorded previously only from Bolivia. Pseudocrossidium pachygastrellum is a distinctive species characterized in the following description: Plants growing in dense turfs. Stems simple or branching (4–13 mm high), transverse section with central strand present, sclerodermas and hyalodermis weakly differentiated; axillary hairs 100–180 µm long, of 3–5 cells, all hyaline. Leaves appressed when dry, weakly spreading when moist, oval-lanceolate, 1–1.5 mm in length, margins revolute to spiraled, entire, margins rolled, differentiated as photosynthetic organs of thin-walled, hollow-papillose cells; costa broad, excurrent as a mucro, superficial cells ventrally differentiated as a multilayered pad of papillose, thin-walled photosynthetic cells, costal transverse section reniform, dorsal and ventral stereid band present, ventral and dorsal epidermis present, the latter weak, guide cells 4–5, hydroid strand present, multiple; upper laminal cells subquadrate, transversally elongated 5–12 × 8–13, papillae restricted to juxtacostal cells (on both surfaces) and submarginal cells (only on ventral surface), basal cells rectangular.