ONION FAMILY 53 



Perianth-segments united Into a tube, with adnate filaments; style not articulate to the 

 capsule; bracts not spathaceous, distinct. 

 Filaments not united into a tube; pedicels articulate; capsule ovate or oblong. 

 Filaments apparently in one series. 



Filaments opposite to the petals wing-appendaged at the base; anthers basi- 



flxed; flowers subcapltate. 2. Dipteeostemon. 



Filaments all deltoid; anthers versatile; flowers umbellate. 



3. Hesperoscobdion. 

 Filaments in two series; the inner adnate to the free part of the petals; anthers 

 versatile. 4. Tritilbia. 



Filaments united into a tube; pedicels not articulate; capsule triquetrous, subglobose. 



5. ANDBOSTEPHIUM. 



1. ALLIUM (Toum.) L. Onion, Garlic, Leek, Chives. 



Bulb crowning a persistent rootstook; outer coat more or less flbrous. 



Leaves terete and hoUow; umbels dense, subcapltate. 1. A. sibiricum. 



Leaves flat or channeled, not hollow. 



Umbels rarely nodding; petals and sepals long-acuminate; capsule not crested. 

 Stamens and styles exserted. 2. A. validum. 



Stamens and styles included, half as long as the petals. 3. A. brevistylum. 

 Umbels nodding; petals and sepals obttise or acute; capsule 6-crested; stamens 

 and style exserted. 

 Leaves roimded-convex on the back, not keeled, Ivmate in cross-section. 



4. A. recurvatum. 

 Leaves almost flat or keeled, somewhat broadly V-shaped in cross-section. 

 Umbels many-flowered ; leaves 3-5 mm. wide. 5. A. cernuum. 



Umbels few-flowered; leaves less them 3 mm. wide. 6. A. neo-mexicanum. 

 Bulbs without a rootstock. 

 Outer bulb-coat flbrous. 



Umbels bulblet-bearing; flowers few or sometimes none. 



Capsule with 6 rounded crests. 7. A. fibrosum. 



Capsule not crested. 



Petals and sepals ovate. 8. A. rubrum. 



Petals and sepals oblong-lanceolate. 9. A. canadense. 



Umbels not bulblet-bearing. 



Capsule not crested; involucre usually 3-leaved. 



Petals and sepals with a thick rounded keel. 10. A. aridum. 



Petals and sepals not thickened on the back. 11. A. NuUallii. 



Capsule crested. 



Petals and sepals more than 1 cm. long; peduncles often 2 or 3; sheaths 

 loose; bracts 3. 12. A. macropetalum. 



Petals and sepals less than 1 cm. long; peduncles solitary; sheaths close. 

 Bracts broadly ovate, usually 2, in flowers not reflexed; flowers white 

 or light rose; several layers of the bulb-coat flbrous. 

 Plant 1-3 dm. high; pedicels 8-12 mm. long; petals and sepals 

 about 5 mm. long. 13. A. textile. 



' Plant 2-6 dm. high; pedicels 12-25 mm. long; petals and sepals 



6-8 mm. long. 14. A. Geyeri. 



Bracts lanceolate, usually 3, soon reflexed; only outer bulb-coat flbrous; 

 flowers red-purple. 15. A. Pikeanum. 



Outer bulb-coat not flbrous, but often more or less reticulate. 

 Petals more or less serrulate or denticulate on the margins. 



Petals and sepals acuminate, the former serrulate near the apex. 



Petals and sepals long-acuminate, one-half longer than the stamens. 



16. A. acuminatum. 

 Petals and sepals abruptly acuminate, only slightly longer than the sta- 

 mens. 17. A. cuspidatum. 

 Petals and sepals obtuse, delicately denticulate below with spreading papillae. 



18. A. simillimum. 

 Petals entire, neither serrulate nor denticulate. 



Ovary and capsule crestless or indistinctly 3-crested. 

 Petals and sepals obtuse or barely acutish. 



Leaves much longer than the scape. 18. A. similUmum. 



Leaves shorter than the scape. 19. A. scillioides. 



Petals and sepals acute or acuminate. 



Stamens exserted. 20. A. incisum. 



Stamens included. 



Reticulations of the bulb-coat irregular, narrow, with curved sides ; 



the outer coat in age becoming flmbrillate. 20. A. flbrillum. 

 Reticulations of the bulb-coat trapezoid, or elongated pent- or hex- 

 agonal; the sides not strongly curved; no flmbrillae. 

 Sepals and petals neither gibbous at the base, nor keeled on the 

 back. 

 Involucres 3-leaved; petals and sepals little exceeding the 



stamens. 22. A. Iribracteatum. 



Involucres 2-leaved; petals and sepals at least half longer 

 than the stamens. 

 Petals and sepals half longer than the stamens; pedicels 



8-15 mm. long. 23. A. Diehlii. 



Petals and sepals twice as long as the stamens; pedicels 

 about 4 mm. long. 24. A. minimum. 



Sepals and petals gibbous at the base and more or less keeled 

 on the back below. 



