| Sự chẩn đoán |
Holdfast shield-shaped to discoid, massive in some where 2 or more thalli arise from a fused holdfast; stem up to 25 mm long, cylindrical, warty. Primary branches terete, smooth. Secondary branches terete, alternately attached irregularly on the primary branch, smooth. Leaves of secondary branches of vegetative thallus mainly ovate-lanceolate to oblong to linear-lanceolate; base unequal; margin generally serrate, entire in some; apex generally obtuse to acute; midrib distinct but disappearing near apex; cryptostomata numerous and scattered. Leaves in fertile materials mainly linear to linear-lanceolate, some linear-oblanceolate, up to 40 mm long and 4 to 5 mm wide; base acute, slightly unequal; margin dentate-serrate, entire in some; apex narrowly acute; midrib distinct. Cryptostomata sparse
in leaves of primary laterals, sparse and scattered in leaves of secondary laterals, but distinct and with tendency to be arranged in rows in narrow leaves of terminal branches. Vesicles numerous, spherical or obovate, blunt; base plain or ear-like or with narrow extended margin; mainly small in fertile materials; racemose; vesicles 1 to 2 mm long, with very short stalks, 1 or less than 1 mm long. Plant dioecious. Male receptacles racemose, up to 15 mm long, pinched in here and there, 0.3 to 0.5 mm in diameter (in dried material) with blunt tip. Female receptacles racemose; receptacular branches compressed to triquetrous, with edges or margins finely serrate to dentate, up to 6 mm or sometimes longer, sometimes slightly twisted. Primary branches up to 80 cm (rarely to 175 cm) in length (Ref. 80758). |
