| Diagnosis |
Small discoid holdfast; stem very short, mostly less than 1 cm long, terete. Primary branches crowded at stem apex, appearing almost sessile on holdfast; filiform, terete. Secondary and terminal branches terete, slightly to irregularly lumpy near their bases because of leaf scars, which are arranged alternately along primary branches at irregular intervals, farther apart near base and closer and crowded toward distal ends. Leaves on primary and secondary branches on younger thalli relatively longer than those at distal portions, generally obovate-oblanceolate, up to 12 mm long, 4 mm wide; base asymmetrical, acuminate to long and narrow, segment gradually grading, giving the leaf a long-stalked appearance; margin of basal half of leaf generally entire, distal half coarsely and irregularly serrate; tip acute, obtuse to rounded; midrib apparent but disappearing below tip; cryptostomata distinctly elevated, scattered. Leaves of terminal branches and those associated with receptacles generally linear to linear-oblanceolate, appearing lumpy because of elevated cryptostomata; margin entire or with few teeth; midrib not apparent; cryptostomata on leaves and floats marked by presence of hairs originating from opening (ostiole). Vesicles small, mainly obovate to sometimes oblong-obovate, less than 2 mm long, 1.5 mm wide, slightly compressed in some, lumpy in appearance because of presence of elevated cryptostomata; stalk short, less than 1/2 the length of vesicle; attached at base of receptacle or arising directly from the receptacular branch (zygocarpic); those attached to tip of receptacular branch appear long-stalked. Male receptacular branches terete, distinctly warty, simple or branched, up to 10mm long. Female receptacular branches simple or branched, highly warty, terete near base and slightly compressed toward distal ends, with or without teeth. Primary branches up to 50 cm in length (Ref. 80758). |