IRIDACEAE. 105 



outer; stamens inserted on the bases of the outer perianth- 

 segments; ovary 3-celled; divisions of the style petal-like, 

 arching over the stamens, bearing the stigmas immediately under 

 their mostly 2-lobed tips; style-base adnate to the perianth-tube. 



Bracts largely scarious; rootstock stout. /. missouriensis. 

 Bracts green, not scarious, rootstocks slender. 



Flower solitary, purple; capsule oblong. /. tenax. 



Flowers usually 2, whitish; capsule globose. I. tenuis. 



Iris missouriensis Nutt. Rootstocks stout, short, branched; stems 20-50 

 cm. tall, naked or with one or two leaves; leaves pale or glaucous, usually 

 shorter than the stem, 5-8 mm. wide; flowers violet-blue, rarely white, 2-4 

 in p ach umbel; bracts scarious, 2-6 cm. long, acute; sepals narrowly clawed, 

 5-6 cm. .long, the honey guides yellowish; petals erect, shorter; capsule oblong- 

 obovoid, somewhat 3-angled; seeds brown. 



Whidby Island, Gardner; not otherwise known in our limits; common in 

 the interior. 



Iris tenax Dougl. Leaves numerous, 30-50 cm. long, 4 mm. broad, acumi- 

 nate; stems shorter than the leaves, each bearing a solitary flower; sepals ob- 

 long, 5 cm. long, purple; petals spatulate, nearly as long. 



Prairies from Chehalis County, Washington, southward. 



Iris tenuis Wats. Stems 20-25 cm. high, bearing several short leaves, 

 usually 2-flowered; leaves 8-10 mm. broad, about equalling the stems; flowers 

 white marked with yellow and purple; petals emarginate. 



Cascade Mountains of northern Oregon along the Clackamas River. 



130. SISYRINCHIUM. Blue-eyed Grass. 



Perennial tufted slender herbs, with short rootstocks; stems 

 simple or branched, 2-edged or 2-winged; leaves linear, grass- 

 like; flowers rather small, mostly blue, terminal, umbellate, with 

 a pair of erect green bracts; perianth-tube short or none, the 6 

 spreading segments oblong or obovate, equal; filaments united 

 to the top; ovary 3-celled, each cavity several-ovuled ; style- 

 branches filiform, undivided, alternate with the anthers. 



Stem usually 2-branched. S. birameum. 



Stem always simple. 



Perianth segments 20 mm. long; outer bract 5-7 cm. long. S. macounii. 

 Perianth segments 12-15 mm. long; outer bract 2-5 cm. 

 long. 

 Leaves 1-3.5 mm. broad, firm; stems 1-3 mm. wide. 5. idahoense. 

 Leaves 0.5-1.5 mm. broad, soft; stems 1-1.5 mm. wide. 5. segetum. 



Sisyrinchium birameum Piper. Loosely tufted, 40-50 cm. high, drying 

 blackish; leaves firm, erect, about half as high as the stem; bracts purplish, 

 subequal, shorter than the pedicels; flowers 2-5 on slender pedicels; perianth 

 dark blue with a yellow eye; capsule globose. 



Vancouver, Washington, Piper. 



Sisyrinchium macounii Bicknell. Pale green or glaucescent; stems tufted, 

 simple, 30-50 cm. high; leaves 20-30 cm. long, 1.5-3 mm. wide, very acute, 

 smooth on the margins; spathes green or purple-margined, the outer 4-7 cm. 

 long, the inner 2-3 cm. long; flowers 2—4, slender-pedicelled, purple with a 

 yellow eye; perianth segments aristulate, 2 cm. long. 



Comox and other places on Vancouver Island, Macoun. 



