the base of the pedicel; sepals and petals linear-lanceolate; stamens 6, the anthers 

 longer than (often 2 to 3 times as long as) their filaments; capsules at maturity 

 4 to 8 times as long as thick, including the exserted prolonged slender-subulate 

 beak which remains intact with dehiscence; seeds not tailed. /. nodosus var. 

 texanus Engelm. 



Infrequent along ponds, lakes and streams, in mud of sloughs and on gravel- 

 sand bars of rivers, in n.-cen. Tex. and the Edwards Plateau, summer; endemic. 



36. Juncus brachycarpus Engelm. 



Perennial, the bases subrhizomatous to shortly rhizomatous, whitish; flowering 

 culms stiffly erect, 20-75 cm. long, 1-2 mm. thick near the middle; leaves scat- 

 tered and subappressed along the culms; blades ascending, only slightly arcuate, 

 essentially terete or basally laterally compressed, 1-2 mm. thick near the middle, 

 with strong complete septa and always longer than their sheaths; bract shorter 

 than or equaling the inflorescence; inflorescence terminal, 2-6 (-13) cm. long, of 

 2 to 10 (to 25) heads, sparingly branched; heads round, 7-9 mm. thick, with 25 

 to 60 flowers; bractlet solitary at the base of the short pedicel; sepals 2.7-3.4 mm. 

 long, about 0.8 mm. broad; petals 2.2-2.3 mm. long, about 0.4 mm. broad; sepals 

 and petals greenish with broad hyaline margins, turning golden brown medially at 

 maturity or slightly darker terminally; stamens 3; capsule obovoid, 1.5-2.2 mm. 

 long, about 1 mm. thick, abruptly apiculate, promptly and completely dehiscent; 

 seeds not tailed. 



Frequent in moist loamy soils, coastal savannah, roadside depressions, marshes, 

 and in water of small ponds and seepy areas, in Okla. (Waterfall), e. and s.e. 

 Tex., rare inland to n.-cen. Tex. and n. part of Rio Grande Plains, spring-early 

 summer; e. and s.e. U.S. inland to O., Mich., 111., Mo. and Okla. 



37. Juncus acuminatus Michx. Fig. 326. 



Tufted perennial; culms 14-80 cm. long, erect, 1-3 mm. thick near the middle; 

 leaves few at the base, mostly scattered on the culm; blades strongly laterally 

 compressed, 1-3 mm. thick near the middle, toward the tip very narrow and 

 nearly terete, with complete but rather weak septa; bract much shorter than the 

 inflorescence; inflorescence terminal, variable, 3-15 cm. long, not or sparingly or 

 much and repeatedly branched, in the typical form of (25 to) 40 to 60 hemi- 

 spherical to turbinate 2 to 10-flowered glomerules, in the f. sphaerocephalus Herm. 

 of 2 to 25 nearly round 15- to 60-flowered heads; bractlet solitary at the base of 

 the short pedicel; sepals 3.3-4 mm. long, 0.7-1.2 mm. broad; petals 2.5-3.5 mm. 

 long, 0.3-0.4 mm. broad in the typical form or 0.5-0.7 mm. broad in f. sphaero- 

 cephalus; sepals and petals paleaceous, drying semirigid, stramineous or often 

 terminally a rich-reddish-brown; stamens 3; capsule narrowly ovoid to elliptic- 

 ovoid, 2.5-3.3 mm. long, apically blunt or very bluntly apiculate, completely 

 and promptly dehiscent. 



The typical form is infrequent in wet places in e. Tex., the f. sphaerocephalus 

 locally frequent in wet meadows, on margin of ponds, sloughs and streams, 

 marshes and springy areas, in Okla. (Adair, Atoka, Mayes and Osage cos.), e. s.e. 

 and n.-cen. Tex., the n. parts of the Rio Grande Plains, Edwards Plateau and 

 Trans-Pecos, and Ariz. (Navajo, Coconino, Santa Cruz and Pima cos.), late 

 spring-summer; the typical form in most of e. U.S. w. to Wise, and Tex.; f. 

 sphaerocephalus from N.Y., Pa., Mich., Ind., Mo., Tex., Wash., Calif., Ariz., 

 Chih., Michoac. and probably scattered elsewhere. 



38. Juncus megacephalus M.A. Curtis. Fig. 327. 



Perennial from subrhizomatous bases; flowering culms 45-110 cm. long, 2-2.2 

 mm. thick near the middle; leaves few and mostly scattered along the culm, 

 not crowded basally; blades terete, mostly about 1 mm. thick near the middle, 



637 



