78 JUNCACEAE. 



A. Leaves neither septate nor equitant. 

 i. Leaves not fistulose ; flowers many. 



a. Flowers bracteolate, inserted singly on the branches of the inflores- 

 cence ; leaves narrowly linear, either flat or subterete and channeled, 

 a. Perennials; stem simple (TENUES). 



Seeds long, caudate ; leaves subterete, with a shallow groove above. 



7. J . Vaseyi. 



Seeds not caudate ; leaves flat, but often involute ; lunate in cross- 

 section. 

 Auricles at the summit of the sheaths membranous, whitish ; petals 



and sepals scarcely spreading. 

 Auricles scarcely produced beyond the insertion, scarcely scarious ; 



inflorescence open. 

 Perianth 34 mm. long, equalling the capsule. 



8. /. interior. 

 Perianth 4.5-5 mm. long, exceeding the capsule. 



9. /. arizonicus. 

 Auricles conspicuously produced beyond the point of insertion ; 



flowers few, congested. 10. /. confusus. 



Auricles cartilaginous, yellowish-brown ; petals and sepals spread- 

 ing, ii. /. Dudleyi. 

 P. Annuals; stem branching (BuroNii). 12. /. bufonius. 

 b. Flowers not bracteolate, in true heads on the branches of the inflores- 

 cence ; leaves broad and grasslike (GRAMINIFOLII). 



13. 7. longistylis. 



2. Leaves fistulose (i. e., hollow) ; flowers few, in small heads (CASTANEI). 

 Stem leafy only at the base, but the uppermost leaf often with a long 

 sheath ; petals and sepals about 4 mm. long ; leaves about i mm. in 

 diameter ; lower bract of inflorescence membranous. 



14. 7. triglumis. 



Stem more or less leafy ; leaves about 2 mm. in diameter ; perianth 5-6 

 mm. long; lower bracts foliaceous. 15. 7. castaneus. 



B. Leaves septate. 



1. Leaves terete, not equitant. 



a. Septa poorly developed; heads 1-3 (see 7. triglumis and 7. castaneus). 



b. Septa well developed ; heads usually several (in 7. Mertensianus usually 



only i) (NODOSI). 

 Inflorescence with short branches ; flowers echinate-spreading or the 



lowest of the head reflexed ; capsule narrowly lanceolate. 

 Heads 7-8 mm. in diameter ; leaf-blades erect ; petals usually longer 



than the sepals. 16. 7. nodosus. 



Heads over 10 mm. in diameter; leaf-blades usually spreading; sepals 



longer than the petals. 17. T. Torreyi. 



Inflorescence with elongated branches or in 7. Mertensianus with a single 



head ; flowers erect-ascending ; capsule oblong. 

 Heads several ; leaves terete ; seeds not caudate. 



1 8. 7. trnncatus. 



Heads solitary or rarely 2-3 ; leaves somewhat flattened ; seed usually 

 caudate. 19. 7. Mertensianus. 



2. Leaves equitant, laterally flattened, so that one edge is towards the stem 



(ENSIFOLII). 

 Flower-clusters numerous, small, 5-i2-flowered, light-colored. 



20. J. brunncscens. 

 Flower-clusters few, is-25-flowered. 



Flowers greenish or light-brown ; ligules of the sheath usually without 



auricles. 21. 7. porous. 



Flowers fuscous or very dark -brown ; ligules of the sheath produced into 

 small auricles. 22. 7. saximontanus. 



i. Juncus filiformis L. In wet places from Lab. to Alaska, Pa., Utah and 

 Wash. Reported from Colorado (Coulter), but doubtful. 



