8a3. ELEOCHARIS R. Brown (subg. ELEOCHARIS) sect. PARVULAE T. V. Egorova in An. A. Fedorov, Fl. Evr. Chasti SSSR. 2: 110. 1976.
Plants perennial; rhizomes creeping, 0.1–0.2 mm thick, soft, internodes to 4 cm, scales not evident, often terminating in a 2–4 mm tuber with large, acute, terminal bud, or tubers among culm bases. Culms terete, 2–9 cm × 0.2–0.5 mm, soft, spongy. Leaves: distal leaf sheaths often disintegrating, thinly membranous, apex rounded. Spikelets: basal spikelets absent; proximal scale empty, amplexicaulous; floral scales membranous. Flowers: anthers 0.6–1.2 mm; styles 3-fid, rarely some 2-fid. Achenes trigonous, rarely some biconvex. Tubercles often rudimentary, often narrower than achene summit or sunken in a depression in achene, color and texture either similar to achene summit and tubercle merging with achene, or different and clearly distinct from achene.
Species 2 (2 in the flora): temperate to tropical North America, Central America, South America, West Indies, Europe, North Africa.
Eleocharis sect. Parvulae is usually treated as monotypic. The taxonomy of its species should be carefully studied worldwide. H. K. Svenson (1957) grouped the species of sect. Parvulae with subg. Eleocharis (sect. Eleocharis) ser. Rostellatae and subg. Zinserlingia in E. ser. Pauciflorae (Beauverd) Svenson on the basis of the often poor differentiation between the tubercle and achene. DNA data presented by E. H. Roalson and E. A. Friar (2000) suggest that sect. Parvulae is closely related to 8a1. sect. Eleocharis.
