Flora of the Hawaiian Islands
Literature for Bolboschoenus maritimus subsp. paludosus
Wagner et al., 1990, 1999.
   Cyperaceae -- The Sedge Family Bibliography
      Bolboschoenus maritimus subsp. paludosus
General Information
DistributionIn the Hawaiian Islands, indigenous to Ni`ihau, Kaua`i, O`ahu, Moloka`i, Maui, Hawai`i.
Rhizomes repent, clothed with brown scales, forming ligneous tubers at culm bases and nodes; culms erect, with several nodes, leafy, trigonous, smooth, 30-150 cm tall.
Leaf blades linear, 3-8 mm wide, gradually tapering to an acuminate apex, scabrous on distal margins and midrib toward apex on lower surface, otherwise smooth; basal sheaths brown.
Inflorescences moderately dense, anthelate, consisting of terminal, congested, head-like clusters of 3 to numerous spikelets, ± with 1-4 rays, each terminated by a head-like cluster of spikelets, the rays up to 5 cm long; involucral bracts 2-5, the lower ones much surpassing the inflorescence, the longest up to 30 cm long; spikelets pale brown, ellipsoid, ovoid-ellipsoid, or subcylindrical, terete, 1-2.5 cm long, 0.6-1 cm in diameter, apex subobtuse; glumes pale brown with pale margins, thin, membranous, narrowly ovate, 5-6.5 mm long, ca. 3 mm wide, tapering to an acute, bifid apex, pubescent externally, 1(3)-nerved, the midnerve prolonged ca. 2 mm beyond the apex; perianth bristles 2-6, up to ca. 1/2 as long as the achene, caducous.
Achenes brown, glossy, obovate, 3-4 mm long, 1.8-2.2 mm wide, lenticular, puncticulate, apex apiculate.
2n = 40, 76-77, 80, 86, 90, 96, 104, 106, 110, 114
The only reliable difference between the 2 subspecies is in the spikelet apices, which are rounded and abruptly contracted in subsp. paludosus, and more gradually acute and attenuate in subsp. maritimus.