RUSH FAMILY 351 



II. Thalassici 



Perianth-segments acute and rigid at the apex; capsule ohlong, acute, about equalling the perianth. 



10. /. cooperi. 

 Perianth-segnients broad and scarious at the apex; capsule obovoid, about twice the length of the perianth. 



1 1. /. acittus. 



III. POIOPIIVLI.II 



Annuals; inflorescence exclusive of its leaves more than one-third the height of the plant. 



Capsule oblong to ovoid, 3-4.5 mm. long, closely enclosed by the inner perianth-segments in fruit. 



12. J. bufoiiitis. 

 Capsule subglobose or short-ovoid, 2-3 mm. long; perianth-segments not closely embracing the fruiting 



capsule. . . 13. y. sphaerocarpus. 



Perennials; inflorescence exclusive of its leaves less than one-third the height of the plant. 

 Stem-leaves 1 or 2, rarely wanting; perianth-segments obtuse at the apex. 14. J, gcrardi. 

 Stem-leaves none; perianth segments acute or acuminate. 



Auricles of the leaf-sheaths cartilaginous, opaque and yellowish. 15. /. dudleyi. 



Auricles of the leaf-sheaths membranous, transparent and usually white. 

 Capsule completely 3-celled. 



Stem stout; bracts leaf-like; perianth-segments 3.5-4 mm. long, pungent at apex. 



16. J. brachyphyllus. 

 Stem slender; bracts filiform; perianth-segments 5 mm. long, merely acute at apex. 



17. ]. conjusus. 

 Capsule 1-celIed, the septa extending only half way to the center. 



Leaves over half the length of the stem; perianth-segments with brown scarious margins. 



18. /. occidentatis. 

 Leaves less than half the length of the stem; perianth-segments with white scarious margins. 



19. /. tenuis. 



IV. GrA-MIXIFOLII 



Perennials, only depauperate plants less than 10 cm. high; leaf-blades flat. 



Junction of leaf-blade and sheath inconspicuous, the auricles rutlimentary or wanting; perianth-segments 

 minutely roughened on the back. 

 Perianth longer than the capsule. 

 Seeds not tailed. 



Inner perianth-segments distinctly longer than the outer; flowers usually in many heads; 



montane species. 20. /. orthophyllus._ 



Inner perianth-segments about equalling the outer; flowers in 1 or 2 heads; maritime species. 



21. /. falcatns. 

 Seeds tailed. 22. J. regelii. 



Perianth equalling or shorter than the capsule. 



Perianth-segments 3-4 mm. long, dark brown, except the well defined roughened portion. 



23. /. covillei. 

 Perianth-segments 2-3 mm. long, pale brown, the roughened portion very small or obsolete. 



24. /. obtiisatus. 

 Junction of the leaf-sheath and blade well marked, and the auricles well developed (except in /. macro- 



phyllus): perianth-segments smooth and usually shining. 

 Outer perianth-segments equalling or longer than the inner; capsule with a broad truncate or retuse 



ape.x and slender mucro. 25. J. longistylis. 



Outer perianth-segments sho'rter than the inner; capsule tapering into a stout beak. 



26. /. macrophyUus. 

 Annuals, less than 10 cm. and seldom more than S cm. high; leaf-blades filiform. 



Inflorescence few-flowered or when reduced to 1 flower still retaining 2 bracts at its base. 

 Style 2 or 3 mm. long; anthers longer than the filaments. 27. /. triformis. 



Style about 0.5 mm. long; anthers minute, much shorter than thq filaments. 



28. /. brachystyhts. 

 Inflorescence 1-flowered, subtended by a single bract. 29. J. uiicialis. 



V. NODOSI 



Capsule obovate to linear-lanceolate in outline, more than two-thirds the length of the perianth. 

 Stamens 6. 



Epidermis of the leaves and stems not rugosely roughened. 

 Anthers shorter than the filaments. 



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



30. /. supimformis. 

 Plants without submersed capillary leaves. 



Heads with few to several flowers, turbinate at maturity. 



Perianth and fruiting capsule 5 mm. or more in length; capsule shorter than the 



segments. 31. J. oreganns. 



Perianth and fruiting capsule less than 5 mm. long; capsule longer than the seg- 

 ments. 

 Branches of the inflorescence divaricate; capsule actite below the mucronation; seeds 



transversely lineolate in the reticulations. 32. /. articulatus. 



Branches of the inflorescence erect; capsule obtuse below the mucronatiori; seeds 

 smooth in the reticulations. 33. J. ricliardsouiaiius. 



Heads many-flowered and at maturity spheroidal. 34. J. mcrtetisianus. 



Anthers equalling or longer than the filaments. 



Perianth greenish white or sometimes tinged with red. 35. /. chlorocephahis. 



Perianth dark or pale brown. 



Body of the capsule obtuse or abruptly acute lielow the mucronation. 

 Perianth dark brown. 



Capsule obtuse or truncate. 36. /. badius. 



Capsule abruptly acute; heads often reduced to 1 or 2 and much congested. 



37. /. nevadensis. 

 Perianth pale brown. 38. /. columbiamis. 



Body of the capsule tapering above into a sharp beak: perianth usually pale brown. 



39. /. ditbuis. 



