Flora of the Hawaiian Islands
Monocotyledon Literature for Hyparrhenia rufa
Wagner et al., 1990, 1999.
   Poaceae -- The Grass Family Bibliography
      Hyparrhenia rufa

Common name(s): jaragua, thatching grass
General Information
DistributionNative to tropical and South Africa, widely naturalized.In the Hawaiian Islands, naturalized on Kaua`i, O`ahu, Moloka`i, Maui, Hawai`i.

Perennials or sometimes annuals; culms densely tufted, forming large clumps 3-25 dm tall, nodes long-pilose.
Sheaths sparsely long-pilose, the hairs white, appressed at base, upper sheaths glabrous but with margins ciliate and hairs readily deciduous; ligule a firm, brownish membrane, 1-2.5 mm long; blades flat, glabrous or upper surface hirsute, 30-60 cm long, 2-8 mm wide, narrowed at base.
Inflorescences large, paniculate, with numerous branches, the branches lax or contracted, fasciculate, 5-80 cm long, spathes linear-lanceolate, becoming reddish and rolled around the peduncle, 3-5 cm long, sparsely to densely long-pilose, racemes dull yellow, sometimes red-tinged, (1.5-)2-2.5 cm long, with (7-)9-14 awns per raceme pair, the awns rarely reflexed, with 1 homogamous pair of spikelets at the base of the lowest or of both racemes, raceme-bases unequal, sometimes connate, the upper one 2-3.5(-4) mm long, glabrous, rarely with a few long hairs, the articulation with the peduncle apex glabrous; sessile spikelet (3-)3.5-4.5(-5) mm long, glabrous to pubescent, but usually sparsely covered with stiff red hairs, usually glossy; pedicellate spikelet acute or rarely mucronate, callus 0.2-0.8 mm long, short and rounded to cuneate, narrowly truncate; lemma slender, filiform, ca. 2 mm long, membranous, awn arising from bifid apex, 2-2.5 cm long, golden to copper brown, strongly twisted, geniculate, pubescent; palea lanceolate, ca. 3 mm long.
Caryopsis ellipsoid to ovoid, ca. 3 mm long.
2n = 20, 30, 36, 40