i. 



YAM FAMILY. ^ 



DIOSCOREA L. Sp. PI. ,032. ,753. 

 amily as denned above. [Name in honor of the C.rk nttnnU* 



^S^TOV^^SUTS,:^S^J?^ 



i. Dioscorea villdsa L. Wild Y.-,m-r,.,t. , ft*. 1068.) 



Dioscorea i-illosa L. Sp. PI. 1033. 1753. 

 Rootstock knotted, horizontal, woody, #'-i' 



hick. Stem 6-i5 long, twining or rarely snb- 

 glabrous; leaves ovate, entire, slender- 



ctioled, alternate or the lower opposite or in 4's, 

 acuminate at the apex, cordate at the base, 2 / -6 / 

 long, i '-4' wide, 9~i3-nerved, thin, green and 

 glabrous or nearly so above, pale and more or 

 less pubescent beneath ; petioles often longer than 

 the blades; flowers greenish yellow, nearly ses- 

 sile, the staminate \ ff -iy 2 " broad in drooping 

 panicles 3'-6' long, the pistillate about 3" long in 

 drooping spicate racemes; capsules membranous, 

 yellowish green, 7 // -i2 // long, strongly 3-winged, 

 containing 2 or sometimes only i flat thin-winged 

 seed in each cavity. 



In moist thickets, Rhode Island to Ontario and Min- 

 nesota, south to Florida and Texas. Ascends to 4000 

 ft. in Virginia. June-July. Fruit ripe Sept., per- 

 sistent on the vines into the winter. 



Family 25. IRIDACEAE Lincll. Nat. Syst. Kd. 2, 382. 1836. 



IRIS FAMILY. 



Perennial herbs with narrow equitant 2-ranked leaves and perfect regular or 

 irregular mostly clustered flowers subtended by bracts. Perianth of 6 segment* 

 or 6-lobed, its tube adnate to the ovary, the segments or lobes in two aeries, 

 convolute in the bud, withering-persistent. Stamens 3, inserted on the per. 

 opposite its outer series of segments or lobes; filaments filiform, i! 

 united; anthers 2-celled, extrorse. Ovary inferior, mostly 3-celled; ovules 

 mostly numerous in each cell, anatropous; style 3-cleft, its bran.-he> Niinetiines 

 divided. Capsule 3-celled, loculicidally dehiscent, 3-angled or 3-lobed (some- 

 times 6-lobed), many-seeded. Endosperm of the seed fleshy ; embryo 

 straight, small. 



About 57 genera and 1000 species, of wide distribution. 



Style-branches opposite the anthers, very broad, petal-liki-. J f 



Style-branches alternate with the anthers, slender or filiform. 

 Style-branches 2-cleft; plants bulbous. 

 Style-branches undivided; plants not bulbous. 

 Filaments all distinct; seeds fleshy. 

 Filaments united; seeds dry. 



i. IRIS L. Sp. PI. 38- 17- 



Herbs with creeping or horizontal, often woody and sometimes tuhcr-beariDg roototocl 

 erect stems, erect or ascending equitant leaves, and large regular terminal sometime^ p*i 

 icled flowers. Perianth of 6 clawed segments united below into a tube, the 3 

 spreading or reflexed, the 3 inner narrower, smaller, usually erect, or in some spec 

 as large as the outer. Stamens inserted at the base of the outer perianth-segmeot 

 linear or oblong. Ovary 3-celled; divisions of the style petal-like, arching orer U 

 bearing the stigmas immediately under their mostly 2-Iobed tips; style-base 

 perianth-tube. Capsule oblong or oval, 3-6-angled or lobed, mostly coriaceoa 

 merous, vertically compressed in I or 2 rows in each celt [Greek, rainbow, re 

 variegated flowers.] 



About 100 species, mostly in the north temperate zone. Besides the fa*ta**9^""" 

 occur in the southern and western parts of North America. The names Flo**r* 

 de-lis are applied to the species. 



29 



