A N F Keys
1 Stems round to elliptic in ×-section; sessile flowers and associated bractlets produced as a solitary, dense cluster of flowers (spike) terminal on a shoot with leaves having a sheath with or without a short blade
2 Plant a cespitose, densely compact cushion with terminal, ovoid spikes 2.3−5 mm long; blades on leaves 1.3−8.5 mm long; bractlet subtending flower 1.2−1.5 mm long; perianth (bristles) absent; achene without a persistent, conic style (tubercle) .. Isolepis cernua [pics]
2' Plant strongly clonal, with tufts of shoots arising from creeping rhizomes with terminal spikes > 5 mm long; leaves lacking blades; bractlet subtending flower 2.5+ mm long; perianth (bristles) present; achene with persistent, conic style (tubercle) .. Eleocharis
1' Stems ± 3-sided; inflorescence composed of 2 or more dense clusters of sessile to subsessile flowers (spikes or spikelets)
3 Flowers unisexual; pistil and later achene enclosed by an urn-shaped or flask-shaped sac (perigynium) .. Carex
3' Flowers bisexual; pistil and achene not enclosed by a sac
4 Perianth (bristles) absent; inflorescence terminal, with leaflike inflorescence bracts and flowers arranged in clusters of many elongate spikelets, each spikelet subtended by 2 glumes and having bractlets and flowers arranged in 2 rows (2-ranked) .. Cyperus
4' Perianth (bristles) present; bractlets and flowers helically arranged
5 Plant leafy with conspicuous blades
6 Plant with inflorescence obviously terminal; blades to 600 × 3−18 mm, diverging above closed, membranous triangle of sheath, lacking a ligule; stamens 3, filaments 7.5−8.5 mm long and anthers 3.5−4 mm long; perianth bristles 6, 1.5−2 mm long .. Bolboschoenus maritimus subsp. paludosus [pics]
6' Plant with lateral inflorescences; blades 230−900+ × 5−15(−20) mm, diverging from sheath with 2 ligulelike projects 0.5−0.8 mm long at top; stamens 2, filaments 1.3−1.5 mm long and anthers ca. 0.8 mm long; perianth bristles (3−)4−6, 0.7−1.3 mm long .. Scirpus microcarpus [pics]
5' Plant appearing mostly to lack green blades and having instead long photosynthetic stems; inflorescence often appearing to be lateral by having a green, stemlike extension of the shoot axis project beyond the inflorescence .. Schoenoplectus
(In Progress)
.. Carex barbarae [pics]
.. Carex multicostata
.. Carex aff. obispoensis [pics]
.. Carex spissa [pics]
1 Spikelets cylindric, 5−10-flowered, breaking into 1-fruited units (disarticulating) = rachis internode + achene + bractlet of next node (2−2.5 mm long), spikelets radiating along inflorescence axis (bottlebrushlike); achenes (1.2−)1.5−1.9 mm long .. Cyperus odoratus [pics]
1' Spikelets compressed to flattened, not breaking into 1-fruited units but instead achenes and bractlets abscising from rachis, achenes < 1.5 mm long
2 Plant clonal with tubers forming annual plants and also long, radiating stolons forming new tuber at tip; bractlet subtending flower 2.5−2.9 mm long; filaments ca. 3 mm long and anthers 1.5−1.6 mm long; achenes typically never formed .. Cyperus esculentus var. leptostachyus [pics]
2' Plant lacking tubers and stolons; stamens with filaments and anthers shorter than above
3 Annual; blades of vegetative leaves and green inflorescence bracts typically < 5 mm wide; anthers ±0.4 mm long
4 Leaf sheath only several mm long; blades and green bracts inversely W-pleated; spikelets to 20 radiating from top of axis, 7−9-flowered; stamens 3; achenes (0.4−)0.7−1 × 0.4−0.6 mm, glossy light grayish to brown; roots generally purplish red .. Cyperus erythrorhizos
4' Leaf sheath 40−80+ mm long, with ligulelike projections 0.5−0.8 mm at top; blades and green bracts V-pleated; spikelets many in dense, spheroidal, headlike clusters mostly 5−13 mm diameter; stamens 1−2; achenes 0.55−0.65 × 0.35−0.45 mm, greenish or golden brown to tannish; roots not red .. Cyperus difformis [pics]
3' Perennial herb with well-developed rhizome; most blades and green bracts > 5 mm wide and ± flat along most of length; anthers ± 1 mm long
5 Basal leaves lacking blades (only sheaths), with green blades restricted to inflorescence; inflorescence not densely clustered, haing spreading green bracts and somewhat open arrays of spikelets; stamens 3; bractlet subtending achene prow-shaped, 1.5−1.9 mm long; achenes ellipsoid, 0.7−0.8 × 0.4−0.6 mm, yellowish brown to light brown .. Cyperus involucratus [pics]
5' Basal leaves with green blades as well as inflorescence; inflorescence with spikelets in dense, headlike clusters; stamen 1; bractlet subtending achene broadly lanceolate, 2−2.5 mm long; achenes obovoid with short beak, 1.2−1.4 × 0.5−0.6 mm, light brown to dark brown (blackish) .. Cyperus eragrostis [pics]
(In Progress)
.. Eleocharis macrostachya [pics]
.. Eleocharis radicans
Schoenoplectus (Rchb.) Palla
NAKED-STEMMED BULRUSH
1 Stems sharply 3-angled, triangular in ×-section with deeply concave sides; spikelet cluster tight and appearing lateral ca. 20 mm from tip, spikelets subsessile .. Schoenoplectus americanus [pics]
1' Stems 3-sided with rounded edges; rays of inflorescence visible, entire to scabrous
2 Leaves nearly bladeless; inflorescence loose; spikelets narrowly ovoid, 4−5 × 2−3 mm; perianth bristles 2−4, linear and flat, (1.2−)1.4−2.1 mm long, short-papillate on margins .. Schoenoplectus californicus [pics]
2' Leaves with blades acute-triangular, 4−40 mm long; inflorescence compact; spikelets cylindric-ovoid, 4−17 × 2−3.5 mm; perianth bristles (3−)5−7, tapered from flattened base, 1.8−2 mm long, barbed on margins .. Schoenoplectus acutus var. occidentalis [pics]
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013