Flora of the Hawaiian Islands
Monocotyledon Literature for Cyperus javanicus
Wagner et al., 1990, 1999; Lorence & Wagner, 2019.
   Cyperaceae -- The Sedge Family Bibliography
      Cyperus javanicus

Common name(s): umbrella segde, `ahu`awa, `ehu`awa
General Information
DistributionNative to tropical Africa and Asia.In the Hawaiian Islands, indigenous to Midway, Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Click here for detailed USGS map by Jonathan Price
Coarse, perennial herb with short rhizomes; culms green, glaucous, tufted, robust, 40‒110 cm tall, 3‒5 mm in diameter near the base, obtusely trigonous, minutely granulate.
Leaves usually numerous, usually longer than the culm; blade green, glaucous, and often white-powdery, coriaceous, linear, 8‒12 mm wide, plicate below the middle, flat or with margin inrolled above the middle, septate-nodulose, margin prominently scabrous; sheath dark brown or purplish brown, septate-nodulose.
Inflorescences umbelliform, compound or partially compound, 10‒15 mm long, rays 6‒10, to 12 cm long, spreading, secondary rays, when present, 3‒6, spikes cylindrical to oblong, 1.5‒3 cm long, 8‒12 mm wide, bearing numerous spikelets; involucral bracts 5‒6, the proximal ones much longer than the inflorescence. Spikelets 5‒7-flowered, grayish brown and white-powdery, divergent to slightly reflexed, turgid, lanceoloid to oblong-lanceoloid, 4.5‒6 mm long, 1.8‒2 mm wide, rachilla broadly winged, jointed above the prophyll; glumes brown with reddish brown flecks or lines, subcoriaceous, broadly ovate, 2.8‒3 mm long, 2 mm wide, many-veined, margin whitish hyaline, keel scarcely ridged, obtuse; stamens 3, anthers linear; style long, stigmas 3.
Achenes blackish brown, ellipsoid-obovate, trigonous, 1.4‒1.5 mm long, minutely puncticulate.
David Lorence