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. GBRMANICA, L., 

 the common FLOWER-DE-LUCE (i. e. Fleur-de-Lis), are familiar in gardens. 



2. SIS\ UIIVCIIIUM, L. BLUE-EYED GRASS. 



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

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

 Blender perennials, with fibrous roots, grassy or lanceolate leaves, mostly branch- 

 ing 2-edged or winged stems, and fugacious um belled-clustered small flowers 

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

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



1. S. Bermudiana, L. Scape winged, naked, or 1- 2-leaved; leaves 

 naiTOw 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, Cay.) 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, 4-6 opening in succession. 



THE CROCUS, the CORN-FLAG (GLADIOLUS), the BLACKBERRY LILY (PAR- 

 DANTHUS CHINENSIS), and the TIGER-FLOWER (TIGRIDIA PAv6xiA), are 

 common cultivated plants of the family. 



ORDER 124. DIOSCOREACE^G. (YAM FAMILY.) 



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

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

 regular flowers, with 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-angled or winged pod. 

 Seeds with a minute embryo in hard albumen. Represented chiefly 

 Dy the genus 



1. DIOSCOREA, Plumier. YAM. 



Flowers very small, in axillary panicles or racemes. Stamens 6, at the base 

 of the divisions of the 6-parted perianth. Pod 3-celled, 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. 1>. villosa, L. (WILD YAM-ROOT.) Herbaceous ; leaves mostly 

 alternate, sometimes nearly opposite or in fours, more or less downy undet 



