150 JUNCACEAE 



Leaf -sheaths open; capsule 1-3-celled, with axile or parietal placentae; seeds many. 



1. Juxcus. 



Leaf-sheaths closed; capsule 1-celled, with basal placentae; seeds 3. 2. Juncoides. 



1. JtJNCUS (Tourn.) L. Rush, Wire-grass. 



Caulescent or rarely scapose swamp plants, with glabrous leaves and stems. 

 Leaves with laterally or vertically flattened, or terete leaf-blades, or the latter 

 sometimes wanting; sheaths with free margins. Cymes paniculate, corymbi- 

 form or capitate. Flowers subtended by a bract and sometimes also by 2 bract- 

 lets. Stamens 6 or 3. Capsule 1-celled or by the intrusion of the placentae 

 3-celled. Seeds often tailed or apiculate, reticulate or ribbed, many. 



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. e., 

 with white tails at each end; densely cespitose perennials. 11. 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 flstuiose. 

 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. 



IIL Tenues. 



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



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

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



VI. Graminifolu. 



Flowers solitary on the scape; plant 2-3 cm. high. VII. Unciales. 



Leaves flstuiose {i.e., hoUow); flowers few in small heads; lower sheath bladeless; 



seeds caudate; stamens 6. V. Castanei. 



Leaves septate. 



Leaves terete, not ectuitant. 



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



Septa well 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. 



L 



I. Effusi. 



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



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



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 purphsn 



brown. 

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



actuninate, 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. vallicola. 

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

 brown. 4. J, mexicanus. 



II. Subtriflori. 



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



margins. 5. J. Drummondit. 



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

 Sepals and petals Unear-lanceolate. light brown; capsule acute. G. J. Parryi. 

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



7. J. Hallii. 



IIL TENtJES. 



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

 Seeds apiculate, not caudate; leaves flat, but usually involute, lunate in section. 

 Ain-icles 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. 



Axu-icles conspicuously produced beyond the point of insertion. 



Capsule oblong, narrow, 3-celled, 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 

 cjme. 11. t7. brachyphyllus. 



