Plants perennial, loosely tufted, glaucous. Culms 50-90 cm tall, 0.8-1.5 mm thick, ascending, glabrous; nodes 2-3 mm.
Basal leaves: sheath glabrous or the lowest sparsely pubescent; auricles present on about half the lower leaves, to 0.75 mm; ligule 0.4-0.8 mm, membranous; blade 11-25 cm long, 1-3.5 mm wide, with 10-15 veins, flat to more or less involute, abaxial (lower) surface glabrous, adaxial (upper) surface scabridulous.
Inflorescence spikelike, 8-18 cm long, with 5-6 spikelets, pedicels up to 1 mm; rachis not extended beyond the distal spikelet; middle internodes 16-36 mm long, glabrous.
Spikelets solitary, tangential to the rachis, 15-32 mm long, longer or shorter than the rachis internodes, with 4-6 florets; rachilla internodes mostly scabrous, hispid below the florets; middle internodes 16-36 mm long.
Glumes equal or unequal, glabrous, acuminate; lower glume 3-12 mm long, 3-5-veined; upper glume 6.5-12 mm, 5-7-veined.
Calluses 1-1.2 mm long, longer than wide, with a longitudinal furrow, hairy on either side of the groove, hairs to about 1 mm long. Lemmas 10-12 mm long, rounded on the back, 5-7-veined, scabridulous on the lower portion, scabrous to scabrous-hispid above, tapering into a strong, straight, scabrous awn, 20-40 mm long, awn with 3 veins at the base. Palea 8.8-11.8 mm long, a little shorter than the body of the lemma, intercostal region densely hairy, keels with teeth 0.15-0.3 mm long, tips separated by about 0.25 mm, intercostal region retuse to truncate.
PAPUA-NEW GUINEA: New Guinea.
Brass 4446, collected on marshy banks of the upper Chirima River, Mt. Albert Edward, Central Division, at 3600 m. and [ 8°22'60.00"S, 147°24'1.69"E from Google Earth]
Brass 4732, collected on banks of a grassland stream, Murray Pass, Wharton Range, Central Division, at 2840 m. [ 8°31'60.00"S 147°20'60.00"E for Murray Pass from Google Earth]
Smith 15508 [5°52'S 145°6'E] CANB 240648
Hoogland 7049 [5°22'S 14°29'E - Google Eath, using elevation as an aid
Paijmans 973 [9°39'S 149°0'E] CANB 219409
Paijmans 1264 [5°49S 145°65'E] CANB 222948
Along creeks through tree-fern grassland, in unshaded areas along well used paths with hard subsoil, in poorly drained, brown, fine, sandy clay. 6500-9500 ft.
No information is available about Anthosachne longiseta. Its inclusion in Anthosachne and treatment as an StYW hexaploid is inferred from its morphological similarity to other species of Anthosachne.
Anthosachne longiseta was originally described as species of Brachypodium. It was transferred to Elymus by Veldkamp in 1989 and to Roegneria by Baum, Yen, and Yang in 1991
One of the four specimens seen had unusually short (about 0.1 mm), closely spaces teeth on the paleal keels and keel veins that extended well beyond the intercostal region.
Formal citation of name
The combination for this species in Anthosache has not yet been published. It is in a manuscript that Barkworth and Jacobs will submit shortly.
Hitchcock, A.S. 1936. Papuan grasses collected by L.J. Brass. Brittonia 1(2):104-130.
Specimens from CANB.