Arizona Spikerush

Eleocharis cancellata is very similar to E. bella. The achenes of E. cancellata are relatively broader in relation to their length, the angles and ridges obscure and fewer, and the trabeculae very distinct and faintly wavy at 35X. R. McVaugh and W. R. Anderson (1974+, vol. 13) mentioned possible intermediates with E. acicularis from Mexico. Eleocharis cancellata has been reported from the flora area from three collections: (1) Texas, Jeff Davis County, A. Brant et al. 2237, 1993, originally identified as E. bella; (2) southwestern Texas or northern Mexico (probably from near San Antonio), Parry & Palmer 912, 1879–1880; and (3) Arizona, Santa Cruz County(?), C. Wright 1937, collected in 1851. Although it was also reported from New Mexico (H. K. Svenson 1929), E. cancellata probably does not occur there (R. McVaugh and W. R. Anderson 1974+, vol. 13).

Plants annual(?), densely cespitose; rhizomes obscured among culm bases, delicate, internodes very short, scales not evident. Culms mostly ascending, terete or 4-angled, 2 cm × 0.2–0.3 mm, soft. Leaves: distal leaf sheaths persistent, greenish to whitish, translucent, membranous, apex blunt. Spikelets ovoid, 2–3 × 1 mm, apex acute; floral scales 7–10, 5 per mm of rachilla, bright brown or colorless, medially greenish, ovate to lanceolate, not folded lengthwise, 0.8–1.2(–1.5) × 0.6–0.8 mm, midrib obscure to slightly keeled, apex acute to acuminate. Flowers: perianth bristles absent; anthers orange-brown, 0.2–0.3 mm. Achenes brownish, broadly ovoid to obpyriform, much less than 2 times longer than wide, with angles plus longitudinal ridges ca. 6, rather obscure, 0.5–0.55 × 0.35 mm, apex blunt, trabeculae 15–20, distinct. Tubercles grayish or brownish, often appressed, mostly pyramidal, 0.1 × 0.1 mm.

Tex.; Mexico (San Luis Potosí).

Fruiting fall (Sep).

Wet springy places; of conservation concern; 1700m.

Eleocharis cancellata S. Wats. Proc. Am. Acad 18: 170. 1883.
Annual? Dwarf, cespitose; culms 1.5-4 cm. high, radiating from a vertically branched rootstock, capillary, striate and sulcate, light green ; sheaths closely investing the culm, fugacious ; spikelets 2-4 mm. long, ovate to ovate-lanceolate, acute, the flowers numerous ; scales obtuse, striate, green, with a narrow brown line on each side, the margin and tip hyaline, at maturity often exposing the achenes ; style trifid ; anthers 0.2-0.3 mm. long ; achenes broadly obovate-pyriform, 0.6-0.7 mm. long (including the small conic style-base), white and shining, with 6 longitudinal ribs and about 15 trabeculae in each longitudinal series, and with conspicuous translucent fenestration between the trabeculae ; bristles lacking.
Type locality: San Luis Potosi, Mexico {Schaffner 575). Distribution : Central and northern Mexico ; perhaps New Mexico.