292 IXIACEAE 
late flowers with a persistent perianth. Ovary inferior: styles3 : stigmas entire. Ovules 
2 or rarely one in each cavity, pendulous, anatropous or amphitropous. Capsule broadly 
3-winged, opening through the wings. Seeds flat, membranous-winged. 
1. Dioscorea villósa L. Rootstocks knotted, 1-3 cm. thick : stems twining, 1-5 m. 
long, more or less branched : leaves sometimes whorled below ; blades thinnish, ovate or 
oblong-ovate, 6-15 cm. long, acuminate, entire, bright green above, pale and somewhat 
pubescent beneath, cordate, usually 9-11-nerved ; petioles slender, as long as the blades or 
shorter: staminate flowers 3 mm. broad, whitish, in delicate panicles: sepals and petals 
ovate or oblong ; tube very short : pistillate flowers in simple racemes : hypanthium early 
elongated: capsules 1.5-2.5 em. long, broadly 3-winged, persistent, becoming lustrous and 
dry at maturity : seeds 1-2 in each cavity, broadly thin-winged. 
In thickets, Ontario to Rhode Island and Minnesota, Florida and Texas. Summer. YAM. WILD 
YAM-ROOT. 
FAMILY 3. IXIACEAE Ecklon. Iris FAMILY. 
Perennial, mostly caulescent herbs, with bulb-like or elongated rootstocks. 
Leaves equitant, 2-ranked, commonly elongated. Flowers perfect, regular or 
irregular, solitary or in clusters from spathe-like bracts. Perianth often highly 
colored: sepals and petals nearly equal or often very different, withering-per- 
sistent or fugacious, distinct, or united below. Androecium of 3 stamens, adnate 
to the perianth opposite the sepals. Filaments filiform, distinct or partially 
united. Anthers 2-celled, extrorse. Gynoecium of 3 united carpels. Ovary 
inferior, 3-celled. Styles distinct, entire or parted, sometimes petal-like. Ovules 
numerous, anatropous, on central placentae. Fruit a loculicidally 3-valved cap- 
sule. Seeds numerous in 1 or 2 rows in each cavity. Embryo straight in the 
fleshy or horny endosperm. [Iridaceae Lindl. | 
Styles alternate with the stamens. 
Styles 2-cleft or 2-parted. . NEMASTYLIS. 
Styles entire or stigmas merely emarginate. 
Rootstocks bulb-like. . CALYDOREA. 
Rootstocks not bulb-like, often elongated. 
Filaments distinct: seeds drupe-like. . GEMMINGIA. 
Filaments wholly or partially united : seeds dry. 
Styles opposite or arching over the stamens. 
Styles slender: filaments united into a tube. 
Styles petal-like : filaments distinct. 
1 NEMASTYLIS Nutt. 
Caulescent herbs, with coated bulb-like rootstocks. Stems terete. Leaves alternate : 
blades narrow, elongated, folded. Flowers solitary or several together from two herbaceous 
bracts, fugacious. Perianth usually showy: lobes 6, nearly equal. Stamens 3: filaments 
more or less united. Ovary 3-celled: styles alternate with the stamens, each parted into 
2 filiform segments: stigmas terminal. Ovules numerous. Capsule somewhat elongated, 
loculicidally 3-valved at the apex. 
Leaves or some of them overtopping the inflorescence: perianth-lobes broadest below the middle. 
1. N. acuta. 
Leaves not overtopping the inflorescence: perianth-lobes broadest above the middle. 2. N. coelestina. 
1. Nemastylis acuta (Bart.) Herb. Foliage bright green. Stems 1-6 dm. tall, 
simple or sparingly forked: leaf-blades linear, 1-3.5 dm. long, some at least overtopping 
the inflorescence: flowers 2-3 from a spathe: bracts unequal, the outer shorter: perianth 
light blue or purple, 4-5 cm. broad ; lobes slightly unequal, broadest below the middle: 
capsule turbinate or obovoid-turbinate, 10-15 mm. high. 
On prairies, Tennessee to Kansas, Louisiana and Texas. Spring. 
2. Nemastylis coelestina (Bart.) Nutt. Foliage deep green. Stems 3-6 dm. tall, 
somewhat zigzag: leaf-blades linear, 1-4 dm. long, or more reduced above, none overtop- 
ping the inflorescence: flowers commonly solitary in the spathes: bracts lanceolate or 
linear-lanceolate, the outer shorter: perianth bright blue, about 4 em. broad ; lobes nearly 
Lae mot above the middle: capsule oblong-prismatic, 2-2.5 cm. long, obtusely 
-angled. 
On prairies or in pine woods, Georgia to Florida and Texas. Spring and summer. 
. SISYRINCHIUM. 
. HERBERTIA. 
IRIS. 
an buoy N m 
2. CALYDÒREA Herb. 
Caulescent herbs, with coated bulb-like rootstocks. Leaves mainly basal: blades nar- 
row, sometimes nearly filiform. Flowers usually few from the terminal solitary spathe. 
