Western Rough Sedge

Carex senta is a member of the C. stricta group and is most similar to C. angustata. These two species, which may be sympatric, can be distinguished by C. senta, which lacks prominent bladeless sheaths, larger leathery perigynia with 3–7 veins on each face, and larger achenes. Carex senta is distinguished from C. nudata by the flowering from second-year stems, by the wider inflorescence bract, the broader ellipsoid perigynia, and the red-brown (rather than black) scales. Variation within the species, as well as its relationships with other members of the C. stricta subgroup, merit investigation. Specimens of C. senta from Santa Cruz Island have obovoid, apically rounded perigynia with a 0.1 mm beak, and specimens from Arizona have papery perigynia. Collections from New Mexico identified as C. senta are C. stricta.

Plants not cespitose. Culms acutely angled, 50–100 cm, scabrous. Leaves: basal sheaths red-brown; sheaths of proximal leaves scabrous, fronts with red-brown spots, prominently ladder-fibrillose, apex U-shaped; blades 4–8 mm wide. Inflorescences: proximal bract shorter than inflorescence, 3–5 mm wide. Spikes erect; staminate 2–3; pistillate 2–4; proximal pistillate spike 3–7 cm × 3–5 mm, base cuneate. Pistillate scales dark red-brown to black, shorter than perigynia, apex obtuse, awnless. Perigynia ascending, pale brown with red-brown spots on apical 1/2, 3–7-veined on each face, somewhat flattened, loosely enclosing achenes, thick-walled, ellipsoid or ovoid, 3–3.5 × 2–2.2 mm, somewhat leathery, dull, often scabrous on apical margins, apex obtuse, papillose; beak pale brown or red-brown, 0.2–0.3 mm. Achenes not constricted, dull.

Ariz., Calif.; Mexico.

Fruiting Jun.

Wet meadows along streams or rivers; 0–3000m.

Carex senta Boott, 111. Carex 174. 1867
"Carex anguslata Boott" W. Boott, in S. Wats. Bot. Calif. 2: 242, in part. 1880.
" Carex Jamesii Torr." W. Boott, in S. Wats. Bot. Calif. 2 : 243, in small part. 1880.
Carex auriculata L. H. Bailey, Mem. Torrey Club 1: 19. 1889. (Type from Coloma, California.)
Not C. auriculata Franch. 1886. Carex austromonlana Parish, Bull. So. Calif. Acad. 4 : 108. pi. 15. 1905. (Type from San Bernardino
Mountains, California.) Carex Bishallii C. B. Clarke, Kew Bull. Add. Ser. 8: 70. 1908. (Type from Yosemite, California.) Carex Jamesii var. auslromontana Kiikenth. in Engler, Pflanzenreich 4 20 : 318. 1909. (Based on
C. auslromontana Parish.) Carex nitdala f. firmior Kukenth. in Engler, Pflanzenreich 4-'°: 337. 1909. (Type from Arizona.) Carex nudala f. sessiliflora Kukenth. in Engler, Pflanzenreich 4 20 : 337. 1909. (Type from Amador
County, California.) "Carex nudata W. Boott" Kukenth. in Engler, Pflanzenreich 4-°: 337, as to plant described. 1909. Carex Parishii Mackenzie; Parish. PI. World 20: 177, name only. 1917. Carex Bolanderi Gand. Bull. Soc. Bot. Fr. 66: 296. 1920. (Type from California.) Not C. Bo-
landeri Olney, 1868.
Cespitose and stoloniferous, the stolons long, horizontal, stout, brownish, scaly, the culms rather slender but stiff, 3-10 dm. high, sharply triangular and roughened on angles even to base, sometimes sparsely hirsutulous on the sides, exceeding the leaves, brownish or purplishbrown at base, arising from the middle of the dried-up conspicuous leaves of the previous year, the lower leaves of the flowering year very much reduced; sterile shoots aphyllopodic; leaves of the flowering year with well-developed blades 4-8 to a fertile culm, septate-nodulose, clustered near base, the blades flat, the margins revolute towards apex, channeled towards base, the upper much longer, usually 1-4 dm. long, 3-5 mm. wide, thinnish but firm, lightgreen, papillate, ciliate-serrulate, sparingly hirsutulous beneath, the sheaths hirsutulous, rounded and not sharply keeled dorsally, the lower of the flowering year breaking and becoming filamentose, white-hyaline ventrally, concave at mouth; the ligule longer or much longer than wide; staminate spikes 2 or 3, somewhat scattered, the terminal peduncled, 3-4.5 cm. long, 5 mm. wide, the lateral sessile, 8-30 mm. long, often with 4 or 5 perigynia at base, the scales oblong-obovate, obtuse and hyaline-tipped, purplish-black with narrow white 1-3-ribbed center not extending to apex; lowest with a rudimentary, sometimes shortly prolonged bract; pistillate spikes 1 or 2, remote or approximate, sessile or slightly peduncled, linear to oblong, 2.5-5 cm. long, 5-9 mm. wide, occasionally staminate at apex, densely flowered, or somewhat loosely at base, the 25-100 appressed-ascending perigynia in several to many rows; lowest bract leaflet-like, dark-auricled, sheathless, usually exceeding spike, and from much shorter than to longer than the culm; scales oblong-ovate or oblong-lanceolate, obtuse to shortacuminate, purplish-black with lighter-colored narrow 1 -nerved center not extending to apex, often hyaline-tipped, about half as wide as and slightly to much shorter than the perigynia; perigynia much flattened, plano-convex, broadly ovate or broadly obovate, 3-3.5 mm. long, 2-2.5 mm. wide, puncticulate, granular-roughened, submembranaceous, often strongly purplishdotted, straw-colored, often purplish-brown-tinged, 2^ribbed (the marginal) and slenderly but rather conspicuously few-nerved on both sides, rounded or round-tapering or truncate at base, short-stipitate or sessile, round-tapering at apex, the margins entire or minutely subserrulate, abruptly apiculate, the beak dark-tinged, 0.25 mm. long with entire orifice; achenes lenticular, broadly obovoid, yellowish-brown, sessile, 1.5 mm. long, 1 mm. wide, not constricted in middle, filling lower two thirds of perigynium-body, apiculate, jointed with the rather short slender style; stigmas 2, slender, rather short.
Type locality: Santa Inez Mountains, twenty miles northeast of Santa Barbara, California (Brewer 350).
Distribution: Swampy places in the coastal counties of California, from Alameda to San Diego counties; in the southern mountains; and in the Sierra Nevada as far north as Amador county; also in the mountains of Arizona. (Specimens examined from California, Arizona.)

Carex senta, known as swamp carex, is a species of sedge that was first described by Francis Boott in 1867. It is found in western North America.