RUSH FAMILY 51 



1. JONCUS (Tovirn.) L. Rush, Wike-grass. 



Lower bracts of the inflorescence terete, erect, appearing like a continuation of the 

 stem; inflorescence therefore apparently lateral; stamens 6. 

 Flowers several in a more or less compound panicle; seeds apiculate or acute; peren- 

 nials with long rootstocks. I. Effusi. 

 Flowers 1-5, of which one is subsessile and the others peduncled; seeds caudate, i. c, 

 with white tails at each end; densely cespitose perennials. II. Subtriflori. 

 Lower bracts not appearing as a continuation of the stem, or if so, channeled on the 

 upper side; inflorescence terminal. 

 Leaves neither septate nor equitant. 

 Leaves not flstulose. 

 Flowers many. 



Flowers bracteolate, inserted singly on the branches of the inflorescence; 

 leaves narrowly linear, either flat or subterete and channeled; 

 stamens 6. 

 Perennials, with short cespitose rootstocks; stems simple. 



III. Tenues. 

 Annuals; stem branching; seed apiculate. IV. Bufonii. 



Flowers not bracteolate, in true heads on the branches of the inflorescence; 

 leaves flat, often grass-like; perennials with stoloniferous rootstocks. 



^ VI. Gbaminifolii. 



FlowerssoUtaryonthescape;plaut 2-3cra. high. VII. Uncialbs. 



Leaves flstulose (i. e., hollow) ; flowers few in small heads; lower sheath bladeless; 

 seeds caudate: stamens 6. V. Castanei. 



Leaves septate. 



Leaves terete, not equitant. 



Septa poorly developed; heads 1-3. V. Castanei. 



Septa weU developed; heads usually several (in J. Mertensianus usually only 



one). VIII. NODOSI. 



Leaves equitant, laterally flattened so that one edge is towards the stem; seeds 



apiculate; perennials with creeping rootstocks. IX. Ensifolii. 



I. Effttsi. 

 Stem light green, striate when dry on account of the free hypodermal flbro-vascular 



bundles; sepals and petals green. 1. J. flliformis. 



Stem dark green or at the base purplish, not striate; sepals and petals brown. 



Stem terete; sheath naked or merely bristle-pointed; sepals and petals dark purplish 

 brown. 

 Inflorescence congested; branches 1—3 cm. long; petals and sepals acute or short- 



aciuninate, almost equal in length. 2. J. ater. 



Inflorescence open; branches 4-7 cm. long; sepals long-acuminate, much exceed- 

 ing the acute petals. 3. J. vaUicola. 

 Stem flattened; uppermost sheath often leaf-bearing; sepals and petals not very dark 

 brown. 4. J. mexicanus. 

 II. StlBTRIFlORl. 

 Upper sheaths merely bristle-pointed; petals and sepals with green backs and dark brown 



margins. 5. J. Drummondii. 



Upper sheaths leaf-bearing; green backs of the petals and sepals less prominent. 

 Sepals and petals linear-lanceolate, light brown; capsule acute. 6. J. Parryi. 

 Sepals and petals broadly lanceolate, very dark brown; capsule retuse. 



7. J. Hallii. 

 III. Tenues. 

 Seeds long-caudate; leaves terete with a shallow groove above. 8. J. Vaseyi. 

 Seeds apiculate, not caudate; leaves flat, but usuaUy involute, limate in section. 

 Auricles at the summit of the sheaths membranous, whitish. 



Auricles scarcely produced beyond the insertion, scarcely scarious; petals and 

 sepals scarcely spreading. 

 Perianth 3—4 mm. long, equalling the capsule. 9. J. interior. 



Perianth 4.5-5 mm. long, exceeding the capsule. 10. J. arizonicus. 



Auricles conspicuously produced beyond the point of insertion. 



Capsule oblong, narrow, 3-ceUed, equalling the perianth or nearly so; sepals 

 and petals erect or appressed. 

 Stem stout; leaves short and broad (1.5—2 mm. wide) ; sepals and petals 4-5 

 mm. long, scarious at the base only, stramineous; flowers in an open 

 cyme. 11. J. brachyphyllus. 



Stem slender; leaves narrow and long; sepals and petals 3.5-4 mm. long, 

 scarious to the apex, fuscous; flowers few, congested. 



. 12. Ji confusus. 

 Capsule ovate or oval, 1-celled, three-fotirths as long as the petals or less; 

 petals and sepals spreading. 13. J. tenuis. 



Auricles cartilaginous, yellowish brown; inflorescence greenish; capsule ovate; petals 

 and sepals spreading. 14. J. Dudleyi. 



IV. Bufonii. 



Capsule oblong to ovoid, trigonous, 3—4.5 nun. long, at maturity closely embraced by 

 the ascending petals. 15. J. bufonius. 



Capsule subglobose or short-ovoid, 2—3 mm. long; petals and sepals at maturity loosely 

 spreading, ascending, or squarrose. 16. J. sphaerocarpus. 



V. Castanei. 



Stem leafy only at the base, but the uppermost leaf often with a long sheath; perianth 

 about 4 mm. long; leaves about 1 mm. in diameter; rootstock short, cespitose. 



