294 



IXIACEAE 



Spathes 2 together, or rarely 3. 



Plants smooth (rarely with the bracts obscurely roughened 



in nos. 6 and 8) : leaf-blades mostly 1.5-3 mm. wide. 



Plants drying green : capsules pale, 2-3 mm. high. 6. S. albidum. 



Plants drying dark : capsules dark, 4-6 mm. high. 5. S. sagitti/crurm. 



Plants more or less scabrous (sometimes smooth in no. 8), not 



drying dark : leaf-blades mostly 1-2 mm. wide. 

 Spathes mostly green: outer bract of the second spathe 



slender- prolonged : perianth pale blue. 7. S. scabrellum. 



Spathes mostly red- purple : outer bract of the second spathe 



as long as the inner : perianth deep violet-blue. 8. S. Asheanum. 



** Spathe subtended by an accessory outer slender bract : tufts of 



plants densely fibrillose at the base. 9. S. capillare. 



b. Tufts of plants with both simple and branched scapes, the latter being 



terminated by 1 or 2 peduncles. 

 Scapes wiry, nearly terete : spathes green, mostly narrow and almost 



terete at the base. 10. S. biforme. 



Scapes flattened, distinctly winged : spathes mostly purplish, flattened. 

 Plants drying dark : leaf-blades rather thin : bracts of the spathe 



smooth. 11. S. intermedium. 



Plants not drying dark : leaf-blades rather stiff : bracts rough. 12. S. vcrsicolor. 



B. Scapes branched or bearing 2 or more terminal peduncles. 

 Tufts of plants densely fibrous at the base. 

 Plants drying very dark. 

 Leaves and scapes smooth. 



Bracteal leaf conspicuously elongated; leaf -blades 2-4 mm. 



wide, finely cross-rugulose. 13. S. xerophyllum. 



Bracteal leaf short and narrow : leaf -blades 1-2 mm. wide, not 



rugulose. 14. S.fuscatum. 



Leaves and scapes more or less roughened on the sides : interior 



scales much shorter than the bracts of the spathe. 15. S. inwustatum. 



Plants pale and glaucous, or not very dark when dry. 



Scapes slender, often flexuous, ciliolate-serrulate : plants rather 



bright or deep green : peduncles very short or subfascicled. 16. S. ruflpes. 



Scapes rather stiff or stout : plants pale or glaucous : peduncles slen- 

 der, not fascicled. 

 Scapes flattened and wing-margined or broadly winged. 



Leaf-blades and scapes mostly manifestly serrulate : peduncles 



usually 5-10 cm. long : staminal column 4-5 mm. high. 17. S. fibrosum. 

 Leaf-blades and scapes mostly smooth-edged : peduncles 2-5 



cm. long : staminal column 2-4 mm. high. 18. S. tortum. 



Scapes subterete or narrowly margined. 



Leaves numerous ; blades elongated, becoming flexuous, 2-4 



mm. wide : plants flowering from February to March. 19. S. Floridanum. 

 Leaves few; blades more slender and much narrower and 



shorter : plants smaller, flowering from June to August. 20. S. Nashii, 

 Tufts of plants without fibers, or not densely fibrous at the base. 



a. Plants more or less stiffly erect or erect-ascending ; scapes not usually 

 branched below the middle : peduncles usually shorter than the 

 scape proper: species, except S. graminoides, not occurring west 

 of the Mississippi River, as far as known. 

 Plants drying very dark (except no. 26). 



Scapes and leaf-blades mostly 1-A mm. wide or more : pedicels 



finally much spreading or recurved. 

 Inflorescence not repeatedly dichotomous. 



Capsule thick-walled : bracts of the spathe closely striate- 



nerved, 2-2.5 cm. long. 21. S. solstitiale. 



Capsule thin- walled : bracts of the spathe not closely stri- 



ate-nerved, the inner one 2 cm. long or less. 

 Perianth about 10 mm. long or more. 



Capsules 2.5-4 mm. high, on recurved pedicels : seeds 



few in each cavity. 22. S. recurvatum. 



Capsules 3-6 mm. high, on spreading pedicels. 



Interior scales much shorter than the bracts of the 



spathe : seeds numerous. . 23. S. graminoides. 



Interior scales often equalling the bracts of the 



spathe : seeds 2-3 in each cavity. 24. S. membranaccum. 



Perianth 5-8 mm. long : capsules 1.5-3 mm. long : seeds 



2-3 in each cavity. 25. S. tenellum. 



Inflorescence more or less dichotomous from successive nodes : 



perianth about 5 mm. long, white or perhaps also blue. 26. S. dichotomum. 

 Scapes and leaf-blades mostly 1-2 mm. wide: pedicels erect or 



nearly so. 

 Leaves and scapes mostly smooth-edged, the scapes becoming 



widely flexuous : peduncles very slender, 5-12 cm. long. 27. S. flagellum. 

 Leaves and scapes serrulate, erect : peduncles 3-7 cm. long. 28. S. Miamiensc. 

 Plants pale or bright green, not drying very dark. 



Roots thickened and clustered, becoming 1.5 mm. thick or more : 



Florida species, the plants becoming 50-80 cm. tall. 

 Leaves very long, equalling the tufts ; blades 1.5-2.5 mm. wide : 



capsules thin-walled, subglobose, 5-6 mm. high. 29. S. longifolium. 



Leaves shorter than the scapes; blades becoming 3-4 mm. 

 wide: capsules thick-walled, broadly oblong, 2.5-5 mm. 

 high. 30. S. corymbosum. 



Roots less clustered, not thickened, usually slender and fibrous : 

 plants mostly 15-50 cm. tall. 



