JUNCACEAE 



255 



**Leaf-blacles terete, channeled along the upper side. 



Lowest bract less than 4 times the length of the inflorescence: capsule 



oblong or obovoid, with the ordinai'y dehiscence. 

 Lowest bract rarely less than 4 times the length of the inflorescence: 

 capsule globose-ovoid, breaking up irregularly in age. 

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

 cence. 

 Stems floating, creeping or diffusely spreading: capsule of a subulate type. 

 Stems erect or nearly so: capsule of an obovoid type. 



Perianth at least }^ longer than the capsule: anthers yellow. 

 Perianth equalling or barely exceeding the capsule: anthers reddish 

 brown. 

 Petals lanceolate to ovate-lanceolate, setiform-aeuminate at the 



apex. 

 Petals obovate to oblong, broadly obtuse at the apex and some- 

 times .slightly mucronate. 

 Heads of the inflorescence commonly 5-15, usually 5-10- 



flowered: plants mostly less than 5 dm. tall. 



Heads of the inflorescence numerous, except in depauperate 



plants, usually 2-.5-flowered: plants mostly over 5 dm. tall. 



B. Leaf-blades either terete and not channeled, or flattened or compressed, with 



the flat surfaces not facing the stem. 



Leaf-blades terete, the pith perforated with slender tubes: clusters of the 



inflorescence reduced to a single flower each. 

 Leaf-blades either terete, hollow, and provided with node-like septa, or flat- 

 tened or compressed, or both: clusters of the inflorescence few-many- 

 flowered. 

 Capsule truly subulate. 



Stamens 6, one opposite each sepal and petal: rootatock slender, tuber- 

 bearing at intervals. 

 Stem stout: sepals longer than the petals: capsules barely ex- 

 ceeding the perianth, each with a beak 1-1.5 mm. long. 

 Stem slender: sepals shorter than the petals: capsules conspicu- 

 ously exserted from the perianth, each with a beak 1.5-2 mm. 

 long. 

 Stamens 3, none opposite the petals: rootstock not tuber-bearing, 

 usually short and thickened throughout. 

 Uppermost leaf-sheath with an almost obsolete blade, this seldom 



exceeding 1 or 2 cm. in length. 

 Uppermost leaf-sheath with a normal blade few to several cm. in 

 length. 

 Stamens as long as the petals, the anthers exserted between 



them. 

 Stamens considerably shorter than the petals: anthers included. 

 Leaf-blades flattened and usually with incomplete septa: 

 capsules markedly beaked, the valves in dehiscence 

 curved outward in the middle, but united above by 

 the beak. 

 Leaf-blades slightly compressed, the septa complete: cap- 

 sules beakless, the valves separating throughout in 

 dehiscence. 

 Capsule oblong to Unear-lanceolate in outline, obtuse or acute at the apex, 

 or sometimes mucronate, but not truly subulate. 

 Capsules ]/^-~/i as long as the perianth. 

 Capsules equalling the perianth in length or exceeding it. 



Seeds 0.7-2.5 mm. long, the body tapering at either end into a 

 white tail of varying length. 

 Plant rigid throughout: stems 2-4 mm. in diameter: sepals and 

 petals spinescent: capsules dark red, firm, exceeding the 

 perianth by about }^ their length. 

 Plant with none of its parts unusually stiff or hard: stems less 

 than 2 mm. in diameter, or the capsule not exserted from 

 the perianth by more than 1 mm. 

 Seeds 0.35-0.55 mm. long, the body with a short, rather abrupt, 

 papilla-like, usually dark-colored apiculation at either end. 

 Capsules nearly twice the length of the perianth, the two to- 

 gether 3.5-5 mm. long. 

 Capsules equalling or sometimes about J^ exceeding the 

 perianth, the two together 2-3.5 mm. long. 

 Perianth 2-2.5 mm. long. 



Larger basal leaf -blades with more than 40 septa: capsule 

 green or straw-colored: plants usually over 5 dm. tall. 

 Larger basal leaf -blades with less than 40 septa: capsule 

 dark brown above at maturity. 

 Perianth 2.5-3.5 mm. long, or if less the capsule straw- 

 colored at maturity and the whole plant less than 5 

 dm. tall. 

 Sepals and petals 2.5-3.5 mm. long: capsules ovoid- 

 lanceolate in outline, broadly acute and mucronate, 

 about as long as the perianth. 

 Sepals and petals 2-2.5 mm. long: capsules linear- 

 lanceolate in outline, obtuse and merely apicuhue, 

 about H exceeding the perianth. 



14. J . dichotomus. 



15. J. setaceus. 



16. J. repens. 



17. J. filipendulus. 



18. J. setosus. 



19. J. marginaius. 



20. J. aristulatus. 



21. J. aboriivus. 



22. J. Torreyi. 



23. J. Texanus. 



24. J. megacephalus. 



25. /. scirpoides. 



26. J. polycephalus. 



27. J. validiis. 



28. /. brachycarpus. 



29. J. trigonocarpus 



30. J. Canadensis. 



31. /. diffusissimus. 



32. J. robustus. 



33. /. Elliotlu. 



34. J. acuminatus. 



35. J. debilis. 



1. Juncus effusus L. Plants -5-12 dm. high, densely tufted. Leaves basal, reduced to 

 filiform rudiments few mm. long: inflorescence 2-10 cm. high, occasionally congested; its 



