254 



JUNCACEAE 



FAMILY 2. JUNCACEAE Vent. RUSH 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 adiiate, 

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

 l_3_ ce lled. 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. 

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



1. JUNCUS. 



2. JUNCOIDES. 



1. JUNCUS 



1. J. effusus. 



2. J. <rymnoi'ar)>ii:-. 



3. J. Roernerianut. 



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, and 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>ndipetals 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. bvjonius. 



5. J. trifidui*. 



6. J. Gerardi. 



7. J. secundus. 



8. J. interior. 



9. J. Arizonicus. 

 10. J. Georgianus. 



11. J. brachyphyUiis. 



12. J. tenuis. 



13. J. 



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



