41. Juncus validus Cov. Fig. 330. 



Tufted perennial from a non- or subrhizomatous base; culms 2-10 dm. long, 

 ascending or erect, basally 3-5 mm. thick, mostly 2-4 mm. thick near the middle, 

 olive-gray; leaves several in a basal cluster and scattered along the culm, laterally 

 compressed, slightly arcuate, 3-6 (-8) mm. thick in larger (dorsiventral) dimen- 

 sion, with strong complete septa; bract much shorter than the inflorescence; in- 

 florescence terminal; heads 6 to 76. rounded or often lobulate, 10-15 mm. thick, 

 each with (30 to) 40 to 50 (to 80) flowers; bractlet solitary at the base of the 

 short pedicel; sepals (3-) 3.4-4.2 (-4.5) mm. long, 0.7-1.4 mm. broad; petals 

 (2-) 2.5-3.5 (-4.3) mm. long, 0.5-1 mm. broad; both petals and sepals marginally 

 hyaline (the petals sometimes broadly so) and both semirigid and subspinose at 

 maturity, stramineous-brown or turning dark-brown; stamens 3; capsule 4.5-5 mm. 

 long, brown or golden-brown, subulate; seeds not tailed. 



In swampy ground, seepage areas, on edge of ponds, lakes and streams. We 

 have two varieties. 



Var. validus. Inflorescence widely spreading, 5-25 cm. long, of (12 to) 15 

 to 76 heads and completely promptly dehiscent capsules. In Okla. (Love, Pitts- 

 burg, Osage and LeFlore cos.), abundant in e. and s.e. Tex. and less so w. to 

 n.-cen. Tex. and n. part of Rio Grande Plains; in Coastal States, Ga. to Tex. and 

 inland to Okla. and Mo. 



Var. fascinatus M. C. Johnst. Inflorescences mostly 2-5 cm. long, of 6 to 15 

 heads, with capsules usually tardily dehiscent apically or even with an indehiscent 

 beak. In Tex. in Edwards Plateau area (Central Mineral Region) and s. to n. 

 part of Rio Grande Plains and n.-cen. Tex., uncommon e. to s.e. Tex., summer; 

 endemic. 



42. Juncus diffusissimus Buckl. Fig. 331. 



Tufted weak perennial; culms 25-65 cm. long, erect, 1-2 mm. thick near the 

 middle; leaves few, scattered on the culm; blades ascending, strongly laterally 

 compressed, 1-2 mm. broad in the larger (dorsiventral) dimension, long-tapered 

 to a setaceous tip, with some complete but rather inconspicuous septa; bract 

 much shorter than the inflorescence; inflorescence terminal, widely and repeatedly 

 branched, 5-20 cm. long; glomerules numbering 30 to 70 (to 130) per inflores- 

 cence, hemispherical or narrower, (1- or) 2- to 10-flowered; bractlet solitary at 

 the base of the short pedicel; sepals (2-) 2.6-3.2 mm. long, 0.6-0.8 mm. broad; 

 petals (1.8-) 2.3-3 mm. long, 0.4-0.5 mm. broad; petals and sepals paleaceous, 

 acute but not subspinescent; stamens 3; capsules linear-lanceolate, trigonous, 4-5 

 (-5.2) mm. long, minutely apiculate, 1.5 to 2 times as long as the perianth, 

 golden-brown, completely dehiscent. 



Swampy meadows, margin of ponds, sloughs, streams, and in shallow water 

 in Okla. (widespread), frequent in e. Tex., less so w. to n.-cen. Tex., rare in 

 Edwards Plateau (Central Mineral Region), in moist loamy soil, summer; 

 Coastal States, Ga. to Tex. and inland to Ind., Mo. and Kan. 



43. Juncus debilis Gray. Fig. 331. 



Tufted weak perennial (or annual?); culms 15-30 cm. long, ascending. 0.5-1 

 mm. thick near the middle; leaves few, scattered on the culm; blades ascending, 

 basally slightly laterally compressed, about 1 mm. broad near the middle, with 

 some complete but inconspicuous septa; bract only 1-2 cm. long; inflorescence 

 terminal, repeatedly branched, 3-10 cm. long, with 5 to 35 glomerules which are 

 hemispherical or narrower and 2- to 10-flowered; bractlet solitary at the base 

 of the short pedicel; sepals 2.2-2.8 mm. long, 0.6-0.8 mm. broad; petals 2.3-2.5 

 mm. long, 0.5-0.7 mm. broad; sepals and petals paleaceous, acute but not sub- 



643 



