254 



JUNCACEAE 



1. J. effusus. 



2. J. gymnocarpus. 



3. J. Roemerianus. 



FAMILY 2. JUNCACEAE Vent. KUSH FAMILY. 



Perennial or sometimes annual often tufted herbs, usually grass-like in 

 habit. Inflorescence paniculate, corymbose or umbel-like, compound, or rarely 

 reduced to a single flower. Flowers sometimes collected into dense - heads. 

 Perianth regular, inconspicuous : parts (sepals and petals) 6, chaffy, often quite 

 similar. Androecium of 3 or 6, or rarely 4 or 5, stamens. Anthers adnate, 

 2-celled : sacs introrse, opening by slits. Gynoecium of 3 united carpels. Ovary 

 1-3-celled. Stigmas 3. Ovules 3-many, anatropous. Fruit a loculicidal cap- 

 sule, but sometimes breaking up irregularly. Seeds 3-many, sometimes with 

 caruncular or tail-like appendages. 



Leaf-sheaths open : capsules 1- or 3-celled with axile or parietal placentae : seeds many. 1. JUNCUS. 

 Leaf-sheaths closed : capsules 1-celled with basal placentae : seeds 3. 2. JUNCOIDES. 



1. JUNCUS L. 1 



Caulescent or scapose often swamp-inhabiting herbs, with glabrous foliage. Leaves 

 terete or flattened : sheaths with free margins. Flowers in often apparently lateral pan- 

 icles or corymbs or heads, either singly and with 2 bractlets (prophylla) or when in heads 

 each merely in the axil of a bract. Bracts usually entire. Stamens 6 or 3. Ovary 

 1-celled or by the intrusion of the placentae 3-celled. Seeds often tailed, usually dis- 

 tinctly reticulated or ribbed. RUSH. 



Lowest bract of the inflorescence terete, not markedly channeled, erect, appearing like a continuation 



of the scape, the inflorescence thus appearing lateral. 

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

 Stamens 3 : sepals and petals about as long as the capsule : petals acute or 



acuminate : capsules of an obovoid type. 

 Stamens 6 : sepals and petals about % as long as the capsule : petals obtuse : 



capsules of an ovoid type. 



Flowers not bracteolate, inserted in heads on the branches of the inflorescence. 

 Lowest bract of the inflorescence not appearing like a continuation of the scape 

 (or if so, markedly channeled along the inner side), the inflorescence there- 

 fore usually appearing terminal. 

 A. Leaf -blades with their flat surfaces facing the stem, or terete and channeled, 



not provided with node-like septa, 

 a. Flowers bibracteolate, inserted singly on the branches of the inflorescence, 



sometimes clustered, but never in true heads. 

 * Leaf-blades flat, but sometimes involute in drying so as to appear terete. 



(See also J. dichotomus below). 

 Annual : inflorescence, exclusive of its bracts, more than % the height 



of the plant : anthers shorter than, the filaments. 

 Perennial : inflorescence, exclusive of its bracts, less than % the height 

 of the plant (except sometimes in J. 'Georgianus, ana the anthers 

 then longer than the filaments). 



Inflorescence 1-3-flowered : leaves with fimbriate auricles. 

 Inflorescence several-many-flowered : leaves with entire auricles. 

 Plants caulescent : sepals and petals obtuse. 

 Plants scapose : sepals and petals acute or acuminate. 



Auricles at the summit of the leaf-sheath membranous or scari- 

 ous, whitish. 

 Auricles membranous, scarcely scarious, rarely if at all 



prolonged beyond the point of insertion. 

 Sepals and petals 2.5-4 mm. long : capsule about as long 



as the perianth. 



Flowers and fruit conspicuously secund : perianth 

 2.5-3.5 mm. long : anthers longer than the fila- 

 ments : bract shorter than the inflorescence: cap- 

 sules oval. 



Flowers scarcely or not at all secund : perianth 3-4 



mm. long : anthers shorter than the filaments : 



bracts exceeding the inflorescence: capsules 



ovoid-oblong or oblong. 



Sepals>nd tpetals 4-6 mm. long : capsules shorter than the 



perianth. 



Plants 4-7 dm. tall : anthers and style very short. 

 Plants 1-4 dm. tall : anthers linear, longer than the 



filaments : style often 1-1.5 mm. long. 

 Auricles scarious, markedly prolonged beyond the point of 



insertion. 

 Capsules oblong, about equalling the perianth, 3-celled : 



sepals and petals erect or appressed. 

 Capsules ovoid or oval, % as long as the perianth or less, 



1-celled : sepals and petals more or less spreading. 

 Auricles at the summit of the leaf-sheath cartilaginous, yellow 

 to yellow brown. 



4. J. bvfonius. 



5. J. trifidus. 



6. J. Gerardi, 



7. J. secundus. 



8. J. interior. 



9. J. Arizonicus. 

 10. J. Georgianus. 



11. J, brachyphyllus. 



12. J. tennis. 



13. J. Dudlcyi. 



1 Prepared with the assistance of Mr. Frederick V. Coville. 



