[P. annuale St. John; P. carteri Hosaka; P. degeneri Potzal; P. fauriei var. carteri (Hosaka) Davidse; P. f. var. latius (St. John) Davidse; P. kukaiwaaense St. John; P. malikoense St. John; P. moomomiense St. John; P. ninoleense St. John; P. nubigenum sensu Hitchc. (1922), non Kunth; P. nubigenum Kunth var. latius St. John; P. sylvanum St. John]
(end [1 var. E*])
Cespitose annuals 2-30(-46) cm tall; culms usually branched, puberulent, the nodes puberulent or short-pilose. Leaves cauline; sheaths usually puberulent, auricular hairs often prominent, 1-2.5 mm long; ligule a ciliate membrane, 0.4-1.6 mm long, the membrane rudimentary or 0.1-0.3 mm long, the cilia 0.3-1.5 mm long; blades 1.5- 12 cm long, 0.1-0.4 cm wide (when unrolled), often loosely involute, upper surface pilose, lower surface puberulent.
Panicles 1-11 cm long, axis puberulent or sparsely pilose, branches usually appressed, puberulent or pilose; spikelets 1.5-4.2 mm long, acuminate to acute, glabrous to pubescent; glumes glabrous, short-pubescent, or short-pubescent with a tuft of hairs 0.6-3.5 mm long at apex, first glume as long as spikelet, acute to acuminate, 3-5- nerved, second glume shorter than or subequal to first glume, acute to acuminate, 5-9-nerved; first floret sterile, first lemma shorter than or equalling second glume, glabrous or short-pubescent at least toward apex, 7-nerved, first palea Ve-Vs as long as first lemma; second floret dark brown at maturity, 1.2-1.8 mm long, 0.5-0.7 mm wide, elliptic, smooth, glossy; anthers 0.8-1.1    mm long. Occurring in dry, open, often rocky habitats, including lava flows, rocky shores, raised coralline reefs, and dunes, 0- 400 m, on all of the main islands except Ni ‘ ihau. —Plate 232.
This species is very uniform in its leaf, culm, and panicle morphology but quite variable in spikelet morphology, especially glume length and pubescence. It is on this basis that the following 3 varieties are rec-ognized: var. carteri [incl. Panicum annuale, P. kukaiwaaense, P. malikoense] with ’ spikelets 1.8-2.3 mm long, acute, short- pubescent [Mokoli‘i (Chinaman’s Hat) Islet, Moloka‘i, Maui] (see Herbst & Fay, 1981, 1983, for discussion of status); var. fauriei [incl. P. degeneri, P. moomomiense, P. sylvanum] with spikelets 1.5-2.3 mm long, usually acute, glabrous (0‘ahu, Molokai, Maui, Kaho'olawe, Hawai‘i); and var. latius [incl. P. ninoleense St. John, P. nubigenum sensu Hitchc.] with spikelets 2-4.2 mm long, acuminate to acute, short- pubescent with short to long tufts of hairs at apex of the glumes (all main islands except Ni‘ihau).