Flora of the Hawaiian Islands
Literature for Rhynchospora rugosa
Wagner et al., 1990, 1999. Literature for Rhynchospora rugosa subsp. lavarum
Wagner et al., 1990, 1999.
   Cyperaceae -- The Sedge Family Bibliography
      Rhynchospora rugosa
General Information
DistributionNative to the Neotropics and Hawai`i.
Habit
Perennials without conspicuous rhizomes; culms tufted, 20-70 cm tall, 0.5-0.8 mm wide, 1-2-nodose below inflorescence.
Leaves
Leaves few, basal, 1-2 cauline, linear, 8-30 cm long, 0.8-2.5 mm wide; sheaths up to 4 cm long, green, the basal ones pale brown.
Flowers
Inflorescences of 2-5 small, anthelate partial panicles widely spaced on the upper 2/3 of the culm, the partial panicles solitary at a node, open, corymbiform, with 3-5 filiform branches and clusters of 2-6 subsessile spikelets, 0.8-3 cm long, bracts linear to setaceous, the lower 1-2 longer than the inflorescence, sheathing at base; spikelets brown to reddish brown, ovoid-ellipsoid, subterete, 4-5 mm long, ca. 2 mm wide; glumes 6-8, the middle 3-4 flower-bearing, 2-3 of them perfect, membranous, ovate, apex acute, the slender midnerve prolonged into a short recurved awn, the flower-bearing glumes 3-3.5 mm long, ca. 2 mm wide; perianth bristles 6, 2.5-2.7 mm long, longer than the achene (incl. the style base), antrorsely spinulose; style base deltoid, 0.5-0.6 mm long, ca. 0.5 mm wide at base, gradually narrowed upward to a filiform style.
Fruit
Achenes reddish brown, obovate to obovate-elliptic, ca. 1.5 mm long, 1-1.1 mm wide, faintly transversely rugulose.