460 DIOSCOREACEJE. (YAM FAMILY.) 





the spa the : 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. SISYBINCIIIUM, 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 branch- 

 ing 2-edgcd or winged stems, and fugacious umbellcd-clustered small flowers 

 from a 2-leaved spathe. (Name composed of <rvs, a hog, and pvy\os, 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 

 narrow and grass-like ; divisions of the perianth obovatc, 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 (TIGIU'DIA PAv6xiA), are 

 common cultivated plants of the family. 



ORDER 124. DIOSCOREACEyE. (YAM FAMILY.) 



Plants with twining stems from large tuberous ropts or knotted rootstockx, 

 and ribbed and netted -veined petioled leaves, small dioecious 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 

 oy the genus 



T. DIOSCOREA, Plumicr. 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-valvcd by splitting through the winged angles. Seeds 1 or 2 in each cell, flat, 

 with a mcmbninaceous wing. (Dedicated to the Greek naturalist Diotooride*.) 



1. D. villos:i, L. (WILD YAM-ROOT.) Hi-rburums ; leaves most!} 

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





