Genus i. RUSH FAMILY. 4 6 5 



Family 20. JUNCACEAE Vent. Tabl. 2 : 150. 1799.* 



Rush Family. 



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

 growing in moist places. Inflorescence usually compound or decompound, pani- 

 culate, 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. Juncus. 

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



i. JUNCUS L. Sp. PI. 325 (1753). 



Usually 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 channeled. Inflorescence paniculate or corymbose, often unilateral, sometimes con- 

 gested, bearing its flowers either singly and with 2 bractlets (prophylla), or in heads and with- 

 out bractlets, but each in the axil of a bract ; bractlets almost always entire ; stamens 6 to 3 ; 

 ovary i-celled or by the intrusion of the placentae 3-celled, the placentae correspondingly 

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



About 215 species, most abundant in the north temperate zone. Type species: Juncus a'cutus L. 

 The plants bloom in summer. [Latin, from jungo, to bind, in allusion to the use of these plants 

 for withes.] 



A. Lowest leaf of the inflorescence terete, not conspicuously channeled, erect, appearing 

 like a continuation of the stem, the inflorescence therefore appearing lateral; stem leaves none. 



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



Perianth-parts green, or in age straw-colored. 



Perianth-parts equalling or exceeding the capsule, all acute. 



Stamens 3 ; leaf of the inflorescence much shorter than the stem. 



Capsule without a distinct apical papilla. 1. /. effusus. 



Capsule with a distinct apical papilla. 2. /. conglomerates. 



Stamens 6 ; leaf of inflorescence about equalling the stem, or longer. 3. /. filiformis. 

 Perianth-parts reaching only the middle of the capsule, inner obtuse. 4. /. gymnocarpus. 

 Perianth-parts with a chestnut-brown stripe down either side of the midrib. 5. /. balticus. 



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



Perianth-parts pale brown ; seed tailless. 6. /. Roemerianus. 



Perianth-parts green, or in age straw-colored ; seed tailed. 7. /. maritimus. 



B. Lowest leaf of the inflorescence not appearing like a continuation of the stem, or if so, 

 conspicuously channeled along the upper side, the inflorescence usually appearing terminal. 



1. Leaf-blade transversely flattened (inserted with its flat surface facing the 

 stem), or terete and channeled, not provided with septa. 



* Flowers bracteolate, inserted singly on the branches of the inflorescence, sometimes clustered or 

 congested, but never in true heads. Poiophylli. 

 Annual ; inflorescence, exclusive of its leaves, more than one-third the height of the plant. 



8. /. bufonius. 

 Perennial ; inflorescence, excluding leaves, not one-third the height of the plant. 

 Leaf-blade flat, but sometimes involute in drying._ 



Inflorescence 1-3-flowered ; leaves with fimbriate auricles. 9. /. trifidus. 



Inflorescence, except in depauperate specimens, several-many-flowered ; leaves with 

 entire auricles. 

 Cauline leaves 1 or 2, rarely wanting; perianth-parts obtuse. 10. /. Gerardi. 

 Cauline leaves none ; perianth-parts acute or acuminate. 



Auricles at top of leaf-sheath cartilaginous, yellow when dry. 11./. Dudleyi. 

 Auricles at top of leaf-sheath membranous, whitish or brownish. 



Inflorescence exceeded by its lowest leaf ; flowers not conspicuously secund. 

 Auricles of the upper leaves usually j4"-i^" l° n g> thin > membranous; peri- 

 anth parts widely spreading. 12. /. tenuis. 

 Auricles less than ^4" long, thin only at the margin ; perianth parts appressed 

 to the capsule. 13- J. interior. 

 Inflorescence not exceeded by its lowest leaf ; flowers conspicuously secund. 



14. /. secundus. 



♦Text contributed by Mr. Frederick V. Coville. 



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