254 JUNCACEAE 
FaAMiLY 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 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.! 
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 api 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. 1. J. effusus. 
Stamens 6: sepals and petals about 14 as long as the capsule: petals obtuse: 
capsules of an ovoid type. 2. J. gymnocarpus. 
Flowers not bracteolate, inserted in heads on the branches of the inflorescence. 3. J. Roemerianus. 
Lowest bract of the inflorescence not appearing like a continuation of the scape 
ad if so, markedly channeled along the inner side), the inflorescence there- 
ore usually appearing terminal. 
A. Leaf-blades with their flat surfaces facing the stem, or terete and channeled, 
not provided with node-like septa. 
à. 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 14 the height 
of the plant : anthers shorter than the filaments. 4. J. bufonius. 
Perennial: inflorescence, exclusive of its bracts, less than 14 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. 5. J. trifidus. 
Inflorescence several-many-flowered : leaves with entire auricles. 
Plants caulescent : sepals and petals obtuse. . J. Gerardi. 
Plants seapose: 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: bractshorter than the inflorescence: cap- 
sules oval. 7. J. secundus. 
Flowers scarcely or not at. all secund: perianth 3-4 
mm. long: anthers shorter than the filaments: 
bracts exceeding the inflorescence: capsules 
e 
ovoid-oblong or oblong. 8. J. interior. 
e apr rei 4-6 mm. long : capsules shorter than the 
perianth. 
Plants 4-7 dm. tall: anthers and style very short. 9. J. Arizonicus. 
Plants 1-4 dm. tall: anthers linear, longer than the 
filaments: style often 1-1.5 mm. long. 10. J. Georgianus. 
Auricles scarious, markedly prolonged beyond the point of 
insertion. ^ 
Capsules oblong, about equalling the perianth, 3-celled : 
sepals and petals erect or appressed. 11. J. brachyphyllus. 
Capsules ovoid or oval, 34 as long as the perianth or less, 
1-celled : sepals and petals more or less spreading. 12. J. tenuis. 
Auricles at the summit of the leaf-sheath cartilaginous, yellow à 
to yellow brown. 13. J. Dudleyi. 
! Prepared with the assistance of Mr. Frederick V. Coville. 
