350 JUNCACEAE 



Family 16. JUNCACEAE.* 

 Rush Family. 



Perennial or sometimes annual, grass-like, usually tufted herbs, commonly 

 growing m moist places. Inflorescence usually compound or decompound, panicu- 

 late, corymbose, or umbelloid, rarely reduced to a single flower, bearing its flowers 

 singly, or loosely clustered, or aggregated into spikes or heads. Flowers small, 

 regular, with or without bractlets (prophylla). Perianth 6-parted, the parts 

 glumaceous. Stamens 3 or 6, rarely 4 or 5, the anthers adnate, introrse. 2-celled, 

 dehiscing by a slit. Pistil superior, tricarpous, 1 -celled or 3-celled, with 3-many 

 ascending anatropous ovules, and 3 filiform stigmas. Fruit a loculicidal capsule. 

 Seeds 3-many, small, cylindric to subglobose, with loose or close seed-coat, with 

 or without caruncular or tail-like appendages. 



Eight genera and about 300 species, widely distributed. 



Leaf-sheaths open; capsule 1- or 3-celled, _ many-seeded; placentae parietal or axial. 1. Jiincus. 



Leaf-sheaths closed; capsule 1-celled, 3-seeded, its placenta basal. 2. Juncoides. 



1. JUNCUS L. Sp. PI. 325. 1753. 



Usual!}' perennial plants, principally of swamp habitat, with glabrous herbage, stems leaf- 

 bearing or scapose, leaf-sheaths with free margins, and leaf-blades terete, gladiate, grass- 

 like, or channelled. Inflorescence paniculate or corymbose, often unilateral, sometimes con- 

 gested, bearing its flowers either singly and with 2 bractlets (prophylla), or in head's and 

 without bractlets, but each in the axil of a bract ; bractlets almost always entire ; stamens 

 3 or 6; ovary 1-celled or by the intrusion of the placentae 3-celled, the placentae correspond- 

 ingly parietal or axial ; seeds several-many, usually distinctly reticulated or ribbed, often 

 tailed. [Latin from jungo, to bind, in allusion to the use of these plants for withes.] 



About 215 species, most abundant in the north temperate zone. The plants bloom in summer. Type 

 species, Jiincus aaitus L. 



Lowest leaf of the inflorescence terete, not conspicuously channelled, erect, exactly simulating a continuation 

 of the stem, the inflorescence therefore appearing lateral. 

 Flowers inserted singly on the branches of the inflorescence, each with a pair of bractlets at the, 



base. L Gexuixi. 



Flowers inserted in few-flowered paniculate heads, each in the axil of a bract but without bract- 

 lets. II- Thalassici. 

 Lowest leaf of the inflorescence not exactly simulating a continuation of the stem, or if so conspicuously 

 channelled along the inner side; inflorescence usually appearing terminal. 

 Leaf-blades transversely flattened (inserted with the flat surface facing the stem) not provided with 

 septa. 

 Flowers inserted singly on the branches of the inflorescence, each subtended by 2 bractlets. 



III. PoiOPHYLLII. 



Flowers inserted in true heads on the branches of the inflorescence, in the axils of a single bract 

 but without bractlets. IV. Gramixifolii. 



Leaf-blades terete or gladiate, never transversely flattened, the septa usually conspicuous and complete 

 (except in the species with gladiate leaves). 

 Leaf-blades terete or somewhat compressed but not gladiate, the septa complete. 



V. NODOSI. 



Leaf-blades gladiate, the septa incomplete. VI. Ensifolii. 



L Genuini 



Inflorescence usually 1-3-flowered, rarely 4-5-flowered; seeds with conspicuous white tails at either end. 

 Blade of the uppermost basal leaf -sheath well developed; capsule acute. 1. /. parryi. 



Blade of the uppermost basal leaf-sheath reduced to a mere rudiment; capsule retuse. 



2. /. drummondi. 

 Inflorescence of many flowers, rarely reduced to 3-5 in depauperate plants; seeds not tailed. 

 Stamens 3, opposite the outer perianth-segments. 3. /. effusus. 



Stamens 6, opposite the inner and outer perianth-segments. 

 Anthers about as long as the filaments. 



Stems numerous in dense tufts; inflorescence decompound; capsule globose-ovoid. 



4. /. patens. 

 Stems barely tufted; inflorescence simply umbelloid or nearly so; capsule oblong. 



5. /. filiformis. 

 Anthers much longer than the filaments. 



Leaf-blades usually well developed on the uppermost basal leaf-sheaths; stems compressed. 



6. /. mc.ricanns. 

 Leaf-blades wanting; stem terete. 



Stems smooth or in dried specimens rugulose with irregularly longitudiiial ridges: woody 

 tissue very thin, composed of 1 or 2 rows of vascular bundles and without fascicles of 

 subepidermal strengthening cells. 

 Perianth-segments 4-5 mm. long. ". J. balticus. 



Perianth-segments 5-6 mm. long. S. /. lescurii. 



Stems finely and evenly sulcate, the woody tissue thick, composed of 3-4 rows of vascular 

 bundles and with well defined fascicles of subepidermal strengthening cells. 



9. J. textilis. 



* Text prepared with the assistance of Air. Frederick V. Coville. 



