GENUS 7. 



AMARYLLIS FAMILY. 



535 



summit. Seeds oblong, ribbed. [Greek, referring to the tufts of wool on the perianth.] 



A monotypic genus of southeastern North America, by 

 some authors placed in the Haemodoraceae. 



i. Lophiola americana (Pursh) Coville. Lo- 

 phiola. Fig. 1326. 



Conostylis americana Pursh, Fl. Am. Sept. 224. 1814. 

 Lophiola aurea Ker, Bot. Mag. pi. 1596. 1814. 

 Lophiola americana Coville, Mem. Torn Club 5: 118. 

 1894. 



Stem stiff, erect, terete, glabrous below, white- 

 woolly above, i-2 tall. Leaves equitant, glabrous, 

 much shorter than the stem, the upper ones reduced 

 to bracts ; panicle densely white-woolly, composed of 

 numerous few-several-flowered cymes ; pedicels short, 

 rather stout, erect or ascending ; perianth-segments 

 linear-lanceolate, about 2" long, woolly outside, longer 

 than the stamens and with a tuft of wool at the base 

 within ; capsule about as long as the persistent style, 

 shorter than the perianth. 



Pine barren bogs, New Jersey to Florida. June-Aug. 



I8 3 6. 



Family 28. DIOSCOREACEAE Lindl. Nat. Syst. Ed. 2 : 359. 



YAM FAMILY. 



Herbaceous or slightly woody twining vines with fleshy or woody rootstocks, 

 slender stems, petioled, mostly cordate, several-nerved and reticulate-veined leaves, 

 alternate or the lower opposite or verticillate, and small inconspicuous dioecious 

 or monoecious (in some exotic genera perfect) regular flowers in spikes, racemes 

 or panicles. Perianth 6-parted, that of the pistillate flowers persistent. Stami- 

 nate flowers with 6 or 3 stamens, sometimes with a rudimentary ovary. Pistillate 

 flowers with an inferior 3-celled ovary, 3 styles and 3 terminal stigmas, sometimes 

 also with 3 or 6 staminodia; ovules 2 (rarely i) in each cavity of the ovary, 

 pendulous, anatropous or amphitropous. Fruit a 3-valved, 3-angled capsule in 

 the following genus. Endosperm of the seed fleshy or cartilaginous, enclosing 

 the small embryo. 



About 9 genera and 175 species, mostly natives of America, a few in the Old World. 



i. DIOSCOREA [Plum.] L. Sp. PL 1032. 1753. 



Characters of the family as defined above. [Name in honor of the Greek naturalist 

 Dioscorides.] 



About 1 60 species, numerous in tropical regions, a few in the temperate zones. The large fleshy 

 rootstocks of several tropical species furnish the yams of commerce. Type species : D. sativa L. 



i. Dioscorea villosa L. Wild Yam-root. Colic-root. Fig. 1327. 



Dioscorea villosa L. Sp. PI. 1033. 1753. 



Rootstock slender or stout, simple or branched, 

 horizontal, woody, i'-f thick. Stem 6-i5 long, 

 twining or rarely suberect ; leaves ovate, entire, 

 slender-petioled, alternate or the lower opposite or 

 in 4*8, 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 pubescent or 

 sometimes glabrous beneath; petioles often longer 

 than the blades ; flowers greenish yellow, nearly ses- 

 sile, the staminate i"-ii" broad in drooping panicles 

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

 spicate racemes; capsules membranous, yellowish 

 green, j"-i2" long, strongly 3-winged, with 2 or 

 sometimes only i thin-winged seed in each cavity. 



In moist thickets, Rhode Island to Ontario. Minne- 

 sota, Kansas, Florida and Texas. Rheumatism-root. 

 June-July. Fruit ripe Sept., persistent on the vines 

 into the winter. Consists of several races, by some 

 regarded as distinct species, differing in the amount of 

 pubescence and in the rootstock. The plant identified 

 as D. paniculata Michx., corresponds closely with the 

 Linnaean type. 



