466 JUNCACEAE. VOL. I. 



Leaf-blade terete, channeled along the upper side. 



Lowest leaf of inflorescence not four lengths of the panicle; capsule oblong to obovoid. 

 Seed tailed. 



Capsule as long as the perianth or longer. 15. /. Vaseyi. 



Capsule much shorter than the perianth. 16. /. oronensis. 

 Seed not tailed. 



Perianth iJ4"-ij4" long, plainly exceeded by the capsule. 17. /. Greenei. 



Perianth i%"-2" long, not exceeded by the capsule. 18. /. dichotomus. 

 Lowest leaf of the inflorescence rarely less than four times as long as the panicle ; 



capsule globose-ovoid. 19. /. setaceus. 



** Flowers not bracteolate, in true heads on branches of the inflorescence. GRAMINIFOLII. 

 Stem erect ; capsule oblong or obovoid, obtuse at the apex. 

 Stamens 3, with red-brown anthers ; capsule not mucronate. 

 Inner perianth-parts obtuse or mucronate. 



Heads few, commonly 5-io-flowered. 20. 7. marginatus, 



Heads numerous, commonly 2-5-flowered. 21. J. aristulatus. 



Inner perianth parts setiform-acuminate. 22. /. setosus. 



Stamens 6, with yellow anthers ; capsule mucronate. 23. /. longistylis. 



Stem creeping, floating, or ascending ; capsule subulate. 24. /. repens. 



2. LEAF-BLADE NOT TRANSVERSELY FLATTENED, COMMONLY TERETE, HOLLOW, PROVIDED 

 WITH SEPTA. 



* Leaf-blade usually channeled along the upper side ; septa usually imperfect, not externally evident ; 



inflorescence of 1-4 heads ; plants of arctic or alpine range. ALPINI. 

 Body of the seed Y^" in length or more. 



Leaf-sheath not auriculate. 25. /. castaneus. 



Leaf-sheath auriculate. 26. /. stygius. 



Body of the seed less than y 2 " in length. 



Lowest leaf of inflorescence foliose, erect ; capsule deeply retuse at apex. 



27. 7. biglumis. 

 Lowest leaf of inflorescence membranous, spreading ; capsule obtuse and mucronate at the 



apex. 28. /. triglumis. 



** Leaf-blade not channeled along the upper side (except in /. bulbosus), the septa perfect (except 

 in /. polycephalus} , and usually externally evident; inflorescence, except in depauperate 

 specimens, of several to many heads ; plants not of arctic-alpine range. SEPTATI. 



t Stamens 6, one opposite each perianth-part. 



Heads reduced to one, or rarely two flowers. 



Plant erect ; flowers several-many, paniculate. 29. J. pelocarpus. 



Plant creeping or floating ; flowers i or 2, peduncled or sessile. 30. /. subtilis. 



Heads 2-many-flowered. 



Epidermis not roughened. 



Plants with two kinds of leaves, one normal, the other basal, submersed, and capillary. 

 Plant low, less than 10' high. 31. /. bitlbosits. 



Plant tall, more than 10' high. 32. J. militaris. 



Plants without submersed capillary leaves. 



Capsule oblong, either abruptly acuminate or bluntly acute. 



Branches widely spreading ; capsule sharply acute, tapering into a conspicuous point. 



33. J. articulatiis. 

 Branches usually strict ; capsule broadly acute, or obtuse, with a short point. 



34. /. alpinus. 

 Capsule subulate. 



Leaf-blades erect; inner perianth-parts ( longer than the outer. 35. /. nodosns. 

 Leaf-blades abruptly divergent from the stem ; outer perianth-parts longer than the 



inner. 36. 7. Torreyi. 



Epidermis of the leaves roughened with minute tubercles. 37. /. caesaricnsis. 



tt Stamens 3, none opposite the inner perianth-parts. 



Capsule less than three-fourths as long as the perianth. 38. 7. brachycarpus. 



Capsule more than three-fourths as long as the perianth. 

 Capsule tapering evenly into a prominent subulate beak. 



Leaf-blade vertically flattened and with incomplete septa, only rarely compressed and with 



complete septa. 39. J. polycephalus. 



Leaf-blade terete or nearly so, the septa complete. 40. 7. scirpoidcs, 



Capsule obtuse to acute at the apex, sometimes mucronate, but not prolonged into a beak. 

 Seed 1/3" -i" long. 



Perianth about i" long, the fruiting head not more than 2" high. 41. 7. brachycephalus. 

 Perianth i l / 2 "-2" long, or if shorter, the fruiting head 2" high or more. 



Inflorescence broad ; capsule about as long as the perianth. 42. 7. canadcnsis. 



Inflorescence narrow ; capsule much longer than the perianth. 43. 7. brevicaudatus. 

 Seed \"-\" long. 



Perianth and mature capsule i"-2" long. 



Perianth i%"-2" long, or if less the whole plant not 20' high. 



Perianth equaling or longer than the capsule ; heads several-many-flowered. 



44. 7. acuminatus. 



Perianth shorter than the capsule ; heads 2-7-flowered. 45. 7. debilis. 



Perianth i"-iJ4" long, the whole plant more than 20' high. 46. J. nodattis. 

 Perianth and mature capsules 2" -3" long. 47. 7. diffusissimus. 



