IRIDACEJE. (IBIS FAMILY.) 469 



ORDER 123. IRIDACE^E. (!RIS FAMILY.) 



Herbs, with equitant 2-ranked leaves, and regular or irregular perfect flow- 

 ers ; the divisions of the 6-cleft petal-like perianth convolute in Hie bud in 2 

 sets, the tube coherent with the 3-celled ovary, and 3 distinct or monadelphota 

 stamens with extrorse anthers. Flowers from a 2-leaved spathe, usually 

 showy and ephemeral. Style single : stigmas 3, opposite with the cells of 

 the ovary. Pod 3-celled, loculicidal, many-seeded. Seeds anatropous: 

 embryo straight in fleshy albumen. Eootstocks, tubers, &c. mostly acrid. 

 A rather small family, here represented by only two genera. 



1. IBIS) L. FLOWER-DE-LUCE. 



Perianth 6-cleft; the 3 outer divisions spreading or reflexed; the 3 inner 

 smaller and erect. Stamens distinct, placed before the outer divisions of the 

 perianth, and under the 3 petal-like stigmas. Pod 3-6-angled. Seeds de- 

 pressed-flattened. Perennials with creeping and often tuberous rootstocks, 

 sword-shaped or grassy leaves, and large showy flowers, f Ipi?, the rainbow 

 deified, anciently applied to this genus on account of the bright and varied 

 colors of the blossoms.) See Addend. 



# Stems leafy (l-3 high), often branching: rootstocks thick: flowers crestless, the 



inner divisions (petals) much smaller than the outer. 



1. I. versicolor, L. (LARGER BLUE FLAG.) Stem stout, angled on 

 one side ; leaves sword-shaped (f ' wide) ; ovary obtusely triangular with the sides 

 flat ; pod oblong, turgid, with rounded angles. Wet places; common. May, 

 June. Flowers blue, variegated with green, yellow and white at the base, and 

 veined with purple. 



2. I. Virgiiiica, L. (SLENDER BLUE FLAG.) Stem very slender, 

 terete; leaves narrowly linear (' wide); ovary 3-angled, and each side deeply 

 2-grooved ; pod triangular, acute at both ends. (I. prismatica, Pursh. I. gra- 

 cilis, BigeL) Marshes, Maine to Virginia, and southward, near the coast. 

 June. Flower much smaller than in the last. 



* * Low, almost stemless, 1 - 3-flowered : divisions of the light blue-purple perianth 

 nearly equal : rootstocks slender, and here and there tuberous-thickened, creeping and 

 tufted. 



3. I. veriia, L. (DWARF IRIS.) Leaves linear, grass-like, rather glau- 

 cous, the thread-like tube of the perianth about the length of the divisions, which 

 are all beardless and o-estless ; pod triangular. Wooded hill-sides, Virginia, 

 Kentucky, and southward. April. 



4. I. criStata, Ait. (CRESTED DWARF IRIS.) Leaves lanceolate (3'- 

 5' long when grown) ; those of the spathe ovate-lanceolate, shorter than the 

 thread-like tube of the perianth, which is 2' long and considerably exceeds the divis- 

 ions ; the outer ones crested, but beardless ; pod sharply triangular. Mountains 

 of Virginia, Kentucky, and southward. May. 



5. I. lacustris, Nutt. (LAKE DWARF IRIS.) Tube of the perianth rather 

 shorter than the divisions (yellowish, '- | ; long), dilated upwards, not exceeding 



