Flora of the Hawaiian Islands
Monocotyledon Literature for Rhynchospora caduca
Wagner et al., 1990, 1999.
   Cyperaceae -- The Sedge Family Bibliography
      Rhynchospora caduca
General Information
DistributionNative to the southern United States from southern Virginia southwest to Texas and south to Florida.In the Hawaiian Islands, naturalized on Kaua`i, O`ahu, Maui, Hawai`i.

Perennials with short-creeping rhizomes; culms loosely to moderately densely tufted, 60-120 cm tall, 1.8-3 mm in diameter near base, 3-4-nodose below the inflorescence, trigonous, smooth.
Leaves basal, a few cauline and well-spaced, herbaceous, linear, shorter than the culm, 3-6 mm wide; sheaths 2-5 cm long, the cauline ones green, the basal ones reddish brown or yellowish brown.
Inflorescences of 4-5 well-spaced, anthelate partial panicles, these decompound, 2-7 cm long, 1.5-3 cm wide, moderately dense, the peduncles exserted, branches numerous, 1-3 cm long, once or twice further branched, each bearing 3-5 spikelets, the lowest 2 leaf-like bracts longer than the subtending partial panicle, the upper bracts as long as or shorter than the subtending partial panicle; spikelets brown, solitary or in clusters of 2-3, subsessile, ovate, 3.5-4.5 mm long, ca. 2 mm wide, subterete; glumes 6-8, the middle 3-6 flower-bearing, 2-4 of them perfect, brown to rusty brown, ovate to broadly so, acute, membranous, margins hyaline, the slender and conspicuous midnerve prolonged into a straight mucro or short awn, the flower-bearing glumes 2.8-3.7 mm long, 2-3 mm wide; perianth bristles 6, longer than the achene (incl. the style base); style base deltoid, 0.6-0.8 mm high and wide, ciliate.
Achenes broadly obovate, lenticular, 1-1.6 mm long, 1-1.4 mm wide, transversely undulate-rugose and cancellate with longitudinally oblong cells.