174 IRIDACEAE 



petals ouch 3, often dissimilar but both colored, distinct or united below. 

 Stamens 3, opposite to the sepals; anthers extrorse. Gynoecium of 3 united 

 carpels; ovary inferior, 3-celled; styles distinct, sometimes petal-like. Fruit 

 a loculicidal capsule. Seeds numerous. 



styles alternate with the stamens; filaments more or less united; flowers rather small; 



sepals and petals similar. 

 Filaments united to near the top; flowers blue or white, rarely rose-purple. 



1. SlSYRINCHITJM. 



Filaments united onlj at the base; flowers rose or purple. 2. OLSYNITJM. 



S t y Irs < > p posi te to and arching over the stamens, petal-like ; filaments distinct ; flowers large ; 

 sepals and petals unlike. 3. IRIS. 



1. SISYRINCHIUM L. BLUE-EYED GRASS.* 



Perennial grass-like herbs, ours tufted, with short rootstocks and fibrous 

 roots. Leaves narrowly linear. Scape 2-edged or 2-winged. Flowers in 

 terminal clusters from spathes of 2 bracts. Petals and sepals in ours blue or 

 white, alike, spreading. Filaments monadelphous. Style-branches filiform, 

 alternate with the stamens. Ovules few in each cavity. Capsule subglobose, 

 readily opening at the apex. 



Stems bearing several peduncles from leaf-bearing nodes. 1. S. radicatum. 



Stems simple and leafless, with sessile terminal spathe (casually with a ternu'nal leaf- 

 bearing node and a peduncle) . 

 Outer bract of spathe little or not at all longer than the inner one, rarely surpassing 



it by more than one-third its length. 



Small and slender; flowers 10 mm. or less long; capsules less than 3 mm. high. 



2. S. halophilum. 

 Stouter; flowers 12 mm. or more long; capsules 4 mm. or more high. 



Outer bract 2-3 cm. long; flowers becoming 14 mm. long. 3. S. occidentale. 

 Outer bract 3-6 cm. long; flowers becoming 18 mm. long. 4. .S. idahoense. 

 Outer bract of spathe conspicuously prolonged, sometimes 2-3 times longer than the 



inner one. 



Plant developing capsules among the bases of the leaves different in form from 

 those of the terminal spathes. 5. 5. heterocarpum. 



No basal capsules. 



Stem winged or margined. 



Perianth-segments not emarginate, narrowed to the aristulate tip. 



Stems and leaves mostly 1-2 mm. wide; capsule obovoid-oblong, 6-7 



mm. long. 6. S. alpestre. 



Stems and leaves mostly under 1 mm. wide; capsule obovoid or sub- 

 globose, 3-5 mm. long. 7. S. septentrionale. 

 Perianth-segments more or less retuse or abruptly contracted to the 



aristulate apex. 

 Stems and leaves mostly 1.5-2.5 mm. wide; capsules 4-6 mm. high. 



8. S. angusti folium. 

 Stems and leaves mostly 1.5 mm. or less in width; capsules 2-4 mm. 



high. 

 Bracts of spathe smooth; valves of capsule veinless. 



9. S. mucronatum. 

 Bracts of spathe minutely scabrellous; valves of capsule sparsely 



venose. 10. S. campestre. 



Stem practically marginless. 11. S. inalatum. 



1. S. radicatum Bickn. Stem erect, stout, 2-4 mm. wide, pale, 3-4.5 dm. 

 high; basal leaves 2-3 mm. broad, 1-2 dm. long, hyaline-margined; peduncles 

 5-10 cm. long, unequal; bracts subequal, acute, 17-22 mm. long, scarious-mar- 

 gined; perianth violet-blue, about 10 mm. long; segments short-aristulate; ovary 

 and young capsule densely glandular-puberulent. Wet meadows: Wyo. 

 Utah Nev. Plain Submont. Mv-Jl. 



/ 



2. S. halophilum Greene. Stem erect, wiry and glaucous, 1-3 dm. high, 

 very narrowly winged; leaves 1-2.5 mm. wide; bracts 12-18 mm. long, slightly 

 scarious-margined; perianth-segments abruptly acuminate; capsule scabrous- 

 puberulent. S. leptocaulon Bickn. (?) S. juncellum Greene. Alkaline meadows: 

 Ida. Colo. Calif. Submont. My-JL 



3. S. occidentale Bickn. Stem 1.5-3.5 dm. high, 1-2 mm. wide, stiff, erect, 

 glaucescent; leaves 1-2.5 mm. wide, very acute; bracts green or purplish, slightly 

 scarious-margined, 2-3 cm. long, with broad margins; capsule subglobose 

 glabrate. Wet meadows: Mont. Colo. Nev. Ida. Plain Mont. Je-Jl. 



* Key and notes supplied by Mr. E. P. Bicknell. 



