382 



JUNCACEAE. 



17. J. marginatus. 



18. J. longistylis. 



19. J. repens. 



HOLLOW, PROVIDED 



** 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. 

 Stamens 6, with yellow anthers; capsule mucronate. 

 Stem creeping, floating, or ascending; capsule subulate. 

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

 WITH SEPTA. 



* Leaf -blade usually channeled along the upper side: septa usually imperfect, not externally evi- 

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

 Body of the seed 1 A" in length or more. 



Leaf-sheath not auriculate. 20. J. casfanetts. 



Leaf-sheath auriculate. 21. J. stygius. 



Body of the seed less than ;*" in length. 



Lowest leaf of inflorescence foliose, erect: capsule deepis- retuse at apex. 22. J. bigltnn 

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



apex. 23. J. t right mis. 



H:^ Leaf -blade not channeled along the upper side (except in J. bulbostts), the septa perfect (ex- 

 cept in J. polycephalus), and usually externally evident; inflorescence, except in depauper- 

 ate 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. 24. J. peloca rpns. 



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. 25. J. bulbostis. 



Plant tall, more than 10' high. 26. J. mil i tan's. 



Plants without submersed capillary leaves. 



Capsule oblong, either abruptly acuminate or bluntly acute. 



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



point. 27. J. articulatus. 



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



28. J. Richardsonianus. 

 Capsule subulate. 



Leaf-blades erect; inner perianth -parts longer than the outer. 29. J. nodosus. 



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



inner. 30. J. Torreri. 



Epidermis of the leaves roughened with minute tubercles. 31. J. Caesariensis. 



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



Capsule less than three-fourths as long as the perianth. 32. J. 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. " 33. /. polycephalus. 



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



Uppermost cauline leaf with a well-developed blade. 34. J. scirpoides. 



Uppermost cauline leaf with a rudimentary blade rarely exceeding i' in length. 



35. J. megacephatus. 



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

 Seed V'-i" long. 



Perianth about i" long, the fruiting head not more than 2" high. 36. J. brachycephalns. 

 Perianth i ^"-2" long, or if shorter, the fruiting head 2" high or more. 37. /. Canadcnsis. 

 Seed J"_-K" long. 



Perianth and mature capsule i"-2" long. 



Perianth i^"-2" long, or if less the whole plant not 20' high. 38. J. acuminatiis. 

 Perianth i"-i%" long, the whole plant more than 20' high. 39. J, robitstus. 

 Perianth and mature capsules 2" -3" long. 40. J. diffttsissimus, 



i. Juncus effusus L,. Common Rush. Bog Rush. Soft Rush. (Fig. 919.) 



Juncus effusits L. Sp. PI. 326. 1753. 



Plant i>^ -4 high, densely tufted, erect. Root- 

 stock stout, branching, proliferous; stem soft, 

 merely striate beneath the inflorescence; basal leaf- 

 blades reduced to filiform rudiments; inflorescence 

 many-flowered, i'-4' high, in one form congested 

 into a still smaller compact cluster; lowest bract of 

 the inflorescence 2 / -io / long, much shorter than the 

 stem; perianth i // -i^ // long, its parts green, lan- 

 ceolate, acuminate; stamens 3, the anthers shorter 

 than the filaments; capsule obovoid, 3-celled, muti- 

 cous, regularly dehiscent; seed \"-W in length, 

 obliquely oblong, reticulate in about 16 longitudi- 

 nal rows, the reticulations smooth and two or three 

 times broader than long. 



In swamps and moist places, nearly throughout 

 North America, except the arid and high northern pur 

 tions. Ascends to 3000 ft. in Virginia. Also in Europe 

 and Asia. 



