[Hemicarpha micrantha (Vahl) Pax, more, Hemicarpha micrantha var. minor (Schrad.) Friedland, Isolepis caespitula , Scirpus micranthus Vahl, Scirpus micranthus var. minor (Schrad. ex Roemer & J.A. Schultes) Boivin]
Annual herb, tufted 2 - 20 cm tall Leaves: basal, 1.5 - 10 cm long, to about 0.5 mm wide, linear, parallel-veined, with a sheathing base that encloses the stem. Inflorescence: a terminal, egg-shaped cluster of one to two spikes, 1 - 3 mm long, 1 - 2 mm wide, subtended by leaf-like bracts. Bracts one to two, longest upright, others spreading, 2 - 5 cm long, about 0.5 mm wide. Spikes composed of numerous spikelets. Flowers: minute, subtended by a floral scale, lacking sepals and petals, with one or two scales. Stamen one, exserted. Pistil one. Style linear, two- to three-cleft. Fruit: a one-seeded achene, about 0.5 mm long and 0.3 mm wide, 1.5 to 2.5 times as long as wide, reverse egg-shaped to widely ellipsoid. Seed with a thin, non-adherent wall. Culm: 2 - 20 cm long, to 0.5 mm wide, circular in cross-section, solid. Spikelets: bearing two floral scales. First scale greenish down the middle, yellowish to reddish brown along the sides, 0.5 - 1 mm long, under 0.5 mm wide, more or less diamond-shaped to reverse egg-shaped (but widest at or above the middle). Second scale sometimes absent, to 0.2 mm long and 0.1 mm wide, two-cleft.
Similar species: No information at this time.
Flowering: late June to early October
Habitat and ecology: Local on wet sandy shores of ponds and streams.
Occurence in the Chicago region: native
Etymology: Lipocarpha comes from the Greek words lipos, meaning fat, and carphos, meaning chaff, referring to the inner scale thickness of some species.
Tufted annual, 2-10(-20) cm; lvs to 10 cm נ0.5 mm, resembling the stems; spikes mostly 1-3 per stem, ovoid, 2-6 mm; scales numerous, 1-2 mm, firm, obovate, mucronate or (especially the lower) with a short awn-tip; achene 0.5-0.7 mm. Moist sandy soil; trop. Amer., n. to Me., Minn., and Wash. Most of our plants (as well as the tropical ones) belong to the var. micrantha, with the inner scale ±strongly reduced (sometimes bifid) or obsolete. Var. aristulata Coville (H. drummondii), with a relatively well developed inner scale ±equaling the achene, occurs chiefly in w. U.S., extending e. sporadically to Ohio.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Infrequent to rare in the area shown on the map. Found in wet, sandy places on the borders of lakes and sloughs and in ditches.
Cronquist et al. 1977, FNA 2002, Kearney and Peebles 1969
Common Name: smallflower halfchaff sedge Duration: Annual Nativity: Native Lifeform: Graminoid General: Delicate tufted annual with clustered terete stems 2-20 cm tall. Vegetative: Blades 1.5-10 cm long narrow, scarcely 0.5 mm wide, appearing like slender stems. Inflorescence: Several spikes at the summit of stem, usually 1-3 per stem, sessile, ovoid, 2-6 mm long and 1.5-2.5 mm thick, floral scales 2, firm, widest at or above midlength abruptly contracted to a blunt mucro; inner scale inconspicuous, 0.1-0.2 mm, hyaline, bifid, outer larger, equaling or slightly exceeding achenes; achenes obovoid to broadly ellipsoid, minute, 0.5 mm long. Ecology: Found on wet sandy soils, especially on sand bars and stream banks from 2,500-4,000 ft (610-1219 m); flowers June-September. Notes: Distinguished by the inner scale being 0.1-0.2 mm or absent. Also can be distinguished by the very delicate narrow leaf blades. Ethnobotany: Unknown Etymology: Lipocarpha comes from Greek leipo, meaning to be deficient or wanting, and karphos for chip of straw, micrantha means small flowered. Synonyms: Hemicarpha micrantha, Hemicarpha micrantha var. minor, Scirpus micranthus, Scirpus micranthus var. minor Editor: SBuckley, 2010