460 DIOSCOREACE^E. (YAM FAMILY.) 



the spathe : otherwise much as in the last. — Gravelly shores of Lakes Huron 

 and Michigan. May. 



I. pumila, L., the Dwarf Iris of the Old World, and I. germanica, L., 

 the common Flower-de-Luce (i. e. Fleur-de-Lis), are familiar in gardens. 



2. SISYBINCHIUM, L. Blue-eyed Grass. 



Perianth 6-parted ; the divisions alike, spreading. Stamens monadelphous. 

 Stigmas involute-thread-like. Pod globular-3-angled. Seeds globular. — Low 

 slender perennials, with fibrous roots, grassy or lanceolate leaves, mostly brandl- 

 ing 2-edged or winged stems, and fugacious umbelled-clustercd small flowers 

 from a 2-leaved spathe. (Name composed of avs, a hog, and pvyxos, snout, 

 from a fancy that the hogs are fond of rooting it up.) 



1. S. Bci'inudmiia, L. Scape winged, naked, or 1 - 2-leaved ; leaves 

 narrow and grass-like ; divisions of the perianth obovate, more or less notched 

 at the end, and bristle-pointed from the notch. (Leaves of the spathe almost 

 equal, shorter than the flowers.) — Var. anceps (S. anceps, Cav.) has a 

 broadly winged scape, and the outer leaf of the very unequal spathe longer than 

 the flowers. — Var. mucronAtum (S. mucronatum, Michx.) has a slender and 

 narrowly winged scape, very narrow leaves, those of the spathe sharp-pointed, 

 unequal, one of them usually longer than the flowers. But there are various 

 intermediate forms. — Moist meadows, &c, among grass ; common everywhere. 

 June-Aug. — Flowers small, delicate blue, changing to purplish, rarely whit- 

 ish, 4 - G opening in succession. 



The Crocus, the Corn-flag (Gladiolus), the Blackberry Lily (Par- 

 danthus Chinensis), and the Tiger-flower (Tigridia Pav6nia), are 

 common cultivated plants of the family. 



Order 124. DIOSCOREACEJ3. (Yam Family.) 



Plants ivith twining stems from large tuberous roots or knotted rootstocks, 

 and ribbed and netted-veined petioled leaves, small dioecious 6-androus and 

 regular flowers, tvilli the 6-cleft calyx-like perianth adherent in the fertile 

 plant to the 3-celled ovary. Styles 3, distinct. — Ovules 1 or 2 in each cell, 

 anatropous. Fruit usually a membranaceous 3-angied or winged pod. 

 Seeds with a minute embryo in hard albumen. — Represented chiefly 

 Dy the genus 



1. DIOSCOBEA, Plumier. Yam. 



Flowers very small, in axillary panicles or racemes. Stamens G, at the base 

 of the divisions of the 6-partcd perianth. Pod 3-cellcd, 3-winged, loculicidally 

 3-valved by splitting through the winged angles. Seeds 1 or 2 in each cell, flat, 

 with a membranaceous wing. (Dedicated to the Greek naturalist. Dioscorides.) 



1. I>. Villusa, L. (Wild Yam-root.) Herbaceous ; leaves mostly 

 alternate, sometimes nearly opposite or in fours, more or less downy under- 



