Rhynchospora brachychaeta |
Rhynchospora indianolensis |
|
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West Indian beaksedge |
indianola beaksedge |
|
Habit | Plants perennial, densely cespitose, 20–50 cm; rhizomes absent. | Plants perennial, cespitose, to 100 cm; rhizomes absent. |
Culms | erect to excurved, lax, filiform, leafy, ± terete. |
stiffly erect or ascending, leafy-based, triangular, multiribbed. |
Leaves | exceeded by culm, ascending; blades filiform, ± terete, margins strongly involute, apex trigonous, sulcate, tapering. |
ascending or erect, crowded toward culm base, shorter, more widely spaced distally, longest overtopping or equaling subtended inflorescences; principal blades flat, trigonous distally, 4–6 mm wide, apex attenuate, trigonous. |
Inflorescences | spikelet clusters mostly 2–3, sparse to dense, oblong to broadly or narrowly turbinate; leafy bracts setaceous, exceeding clusters. |
terminal and axillary, compounds of fascicles, nearly umbellate; clusters hemispheric to nearly capitate, 1.5–2 cm wide; 1 cluster nearly sessile, others on slender rays to 7 cm, sometimes penultimate node with single cluster on peduncle 7–12 cm. |
Spikelets | pale redbrown, lanceoloid, 3–3.5 mm, apex acute; fertile scales mostly elliptic, 2–2.5 mm, apex acute, sometimes apiculate. |
light redbrown, lanceoloid, 6–7 mm, apex acute; fertile scales lance-ovate, 5 mm, apex acute to blunt, midrib shortexcurrent or not. |
Flowers | bristles mere nubs or 1–2, to 0.3 mm. |
perianth bristles 6, overtopping tubercle base, antrorsely barbellate. |
Fruits | mostly 2 per spikelet, 1.5–1.6 mm; body redbrown with pale center, lenticular, broadly obovoid to orbicular, margins pale, narrow, flowing to tubercle; surfaces smoothish, or faintly cancellate; tubercle flattened, triangularsubulate, 0.3–0.5 mm. |
1 per spikelet, (5.5–)6–7 mm; body obovoid, 3–4 × 2–2.5 mm, margins thick, crimped, surfaces level or concave, minutely pebbled; tubercle narrowly conic, 2grooved, 3–4 mm, base blunt, stout, capping fruit apex, tip barely exserted. |
Rhynchospora brachychaeta |
Rhynchospora indianolensis |
|
Phenology | Fruiting late spring–fall. | Fruiting early summer–fall. |
Habitat | Moist sandy peaty substrates in savannas or savanna bog transition, ditches, and moist, disturbed areas | Silty shallows of pools, prairie swales, ditches |
Elevation | 0–100 m (0–300 ft) | |
Distribution |
AL; FL; MS; Central America; West Indies |
TX |
Discussion | Rhynchospora brachychaeta is quite possibly adventive; most of its localities in the flora are in disturbed areas near the coast. It is similar to the widespread native R. chapmanii, from which it is distinguished by its more numerous spikelet clusters, the darker spikelets, the achene faces brown with pale centers (rather than pale with brown ends), and the relatively more developed perianth. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Rhynchospora indianolensis was considered by G. Kükenthal to be closely related to, if not the same as, the Cuban R. scutellata Grisebach but with fruit of different dimensions and sculpture. W. W. Thomas (1984) believed the two to be conspecific. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 235. | FNA vol. 23, p. 207. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Phaeocephalum brachychaetum, R. blauneri, R. chapmanii, R. pallida, R. pallida | |
Name authority | C. Wright: Anales Real Acad. Ci. Méd. Fís. Nat. Habana 8: 85. (1873) | Small: Fl. S.E. U.S., 193, 1327. (1903) |
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