204 



JUNCACE.E. 



Juncus. 



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



channelled, or semiterete, not knotted. 

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



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

 Stamens 3 : capsule ovate, apiculate. 



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



small head. 12. J. TRIFORMIS. 



Stem very short and very much branched : peduncles 1-2-flowered. 13. J. KELLOGGII. 

 Taller perennials : stems simple : stamens 6. 



Stems naked : flowers solitary in a diffuse (rarely compact) cyme. 14. J. TENUIS. 

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

 tate or clustered. 



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

 tary or few. 



Spathes short : perianth equalling the capsule. 15. J. FALCATUS. 



Spathes elongated : perianth shorter than the capsule. 17. J. OBTUSATUS. 



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



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



versely : inflorescence terminal : flowers capitate. 

 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. BOLANDERI. 



Sbamens 6. 



Stout : capsule narrow, acuminate. 



Leaves divergent : heads few, very many-flowered : anthers 



shorter than the filaments. 20. J . KODOSUS. 



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. 

 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. 

 Heads usually many and larger : segments lanceolate : anthers 



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



As the last ; anthers much longer : stigmas long-exserted. 25. 



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

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



22. J. NEVADENSIS. 



23. J. OXYMERIS. 



J. XIPHIOIDES. 



J. PH^EOCEPHALUS. 



26. 

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



acuminate. 27. 



J. CHLOROCEPHALUS. 



J. MERTENSIANUS. 



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

 sheaths sometimes bearing terete leaves like the scape : flowers in sessile appar- 

 ently lateral panicles. JUNCUS proper. 



) Flowers clustered, hexandrous: scapes stout, the inner sheaths leaf-bearing : 

 spathes 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 unequal 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, apiculate, brown, nearly 2 lines long : seeds acute at each end or slightly 

 caudate, about line long, very finely ribbed. Proc. Anier. Acad. xiv. 302. J. 

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

 Rep. vi. 376. 



