204 JUNCACE.E. Juncus. 



* * Panicle or head terminal on the naked or leafy stem : leaves flat, 



channelled, or seniiterete, not knotted. 

 Low annuals, with fibrous roots : stems leafy, branched. 



Stamens 6 : capsule oblong : branching from the base : flowers remote. 11. J. BrFoxius. 

 Stamens 3 : capsule ovate, apieulate. 



Stem very sliort with several scape-like peduncles : flowers in a 



small head. • 12. J. trifokmis. 



Stem very sliort and veiymuch branched : peduncles 1-2-flowered. 13. J. Kelloggu. 

 Taller perennials : stems simple : stamens 6. 



Stems naked : flowers solitary in a difl'iise (rarely compact) cyme. 14. J. tenui.s. 

 Stems leafy : leaves flat and grass-like (not equitant): flowers capi- 

 tate or clustered. 

 Stem low, mostly equalling the leaves : ligules none : heads soli- 

 tary or few. 

 Spathes short : j)erianth equalling the capsule. 15. J. falcatus. 



Spathes elongated : perianth shorter than the capsule. 17. J. obtusatu.s. 



Stem taller, exceeding the leaves : ligules present : heads 5 to 9. 16. J. longi.stylis. 



» * * Stems leafy : leaves terete or laterally flattened, knotted trans- 

 versely : inflorescence terminal : flowers caj)itate. 

 Leaves terete or subcompressed. 

 Stamens 3 ; anthers shorter than the filaments : heads few. 



Dwarf: early leaves capillary and floating : heads few-flowered. 18. J. supiniformis. 

 Tall : ligules conspicuous : heads many-flowered. 19. J. Bolaxdeki. 



Stamens 6. 



Stout : capsule nari'ow, acuminate. 



Leav(!s divergent : heads few, very many-flowered : anthers 



shorter than the filaments. 20. J . nodosus. 



Heads numerous in a compound panicle : anthers longer than 



the filaments. 21. J. dubius. 



Slender : capsule oblong, abruptly acute. 



Leaves very narrow : heads small, one to many : anthers longer 



than the filaments. 22. J. Nevadensis. 



Leaves flattened and equitant. 



Stems stout, ancipital : leaves broader. 

 Heads small, numerous in a compound panicle : perianth-segments 

 linear-lanceolate : anthers exceeding the filaments : capsule 

 narrow, attenuate, exserted : ligules present. 23. J. oxymeris. 



Heads usually many and larger : segments lanceolate : anthers 



short : capsule oblong, acute : ligules none. 24. J. xiphioides. 



As the la.st ; anthers much longer : stigmas long-exserted. 25. J. ph^ocephalus. 



Stems low, slender, compressed : leaves very narrow, with ligules. 



Heads 1 or 2 : perianth -segments pale and scarious, often obtuse. 26. J. chlorocephalus. 

 Head solitary, many-flowered : segments very daik, narrowly 



acuminate. 27. J. Mertensianus. 



* Stems leafless and scape-like, from matted rootstocks, sheathed at base ; the 

 sheaths sometimes bearing terete leaves like the scape : flower's in sessile appar- 

 ently lateral panicles. — Juncus proper. 



H- Florvers clustered., hexandrous: scapes stout, the inner sheaths leaf-hearing : 

 spxithes usually shorter than the inflorescence. 



1 . J. robustus, Watson. Scape and leaves 2 to 4 feet high or more, stout, 

 rigid and pungent : panicle compound with very une(pial branches, usually 3 to 6 

 inches long, erect and strict, about equalling or exceeding the spathe : secondary 

 spathes and bracts long-acuminate, equalling or exceeding the flowers : clusters 

 2 - 4-flowered : perianth-segments scariously margined, the outer broadly lanceolate, 

 acute, the inner obovate and deeply emarginate, a line long, exceeding the stamens : 

 style nearly equalling the stigmas : capsule subglobose, narrower at base, rounded at 

 the summit, apieulate, brown, nearly 2 lines long : seeds acute at each end or slightly 

 caudate, about \ line long, very finely ribbed. — Proc. Amer. Acad. xiv. 302. J. 

 acutns, Engelm. 1. c. 438. J. acutus, var. sphcerocarpus, Engelm. in Wheeler's 

 Eep. vi. 376. 



