APOCYNACEAE 933 
white or colored, rotate or funnelform ; lobes induplicate-valvate. Androecium 
of5stamens. Filaments adnate to the corolla-tube. Anthers versatile. Pollen- 
grains 3-angled. Gynoecium compound. Ovary 1-celled, with placentae at the 
sutures. Style entire, terminal. Stigmas terminal, of 2 blades, sometimes 
nearly sessile. Ovules few or many. Fruit a capsule, this indehiscent, irregu- 
larly opening or valvate. Seeds with a smooth or variously roughened testa. 
1. LIMNANTHEMUM J. F. Gmel. 
Aquatic herbs, with floating or creeping stems. Leaves often all basal : petioles elon- 
gated : blades always broad, leathery, or membranous when submerged, with a deep sinus, or 
peltate. Flowers solitary or clustered at the nodes, their pedicels sometimes accompanied 
by tubers. Calyx green: lobes 5, rather narrow. Corolla white or yellow, somewhat 
rotate : lobes 5, surpassing the sepals. Stamens 5: filaments very short, adnate to the base 
of the corolla. Ovary 1-celled. Capsules slightly longer than broad, indehiscent, or open- 
ing irregularly, Seeds with a smooth or tuberculate testa. FLOATING HEART. 
Leaf-blades relatively small: corolla about twice as long as the calyx: capsule slightly longer than the 
calyx : seeds smooth. 1. L. lacunosum. 
Leaf-blades relatively large: corolla about thrice as long as the calyx: capsule about 
twice as long as the calyx: seeds tuberculate. 2. L. aquaticum. 
1. Limnanthemum lacundsum (Vent.) Griseb. Leaf-blades ovate to orbicular- 
ovate, 2-4 cm. long, undulate, sometimes pubescent beneath, deeply cordate : flower-clusters 
usually accompanied by a cluster of slender tubers: calyx usually glabrous, 3-4 mm. long : 
lobes linear-oblong or linear-lanceolate: corolla white, 6-9 mm. broad: capsules slightly 
longer than the calyx : seeds smooth. 
In shallow ponds, Nova Scotia to Ontario, Minnesota, Florida and Louisiana. Spring to fall. 
2. Limnanthemum aquáticum ( Walt.) Britton. Leaf-blades suborbicular to reni- 
form, 5-15 cm. in diameter, undulate or repand, cordate, reticulated and pitted on the lower 
discolored surface: flower-clusters commonly destitute of tubers: calyx 4-5 mm. long: 
lobes oblong to lanceolate : corolla white, 12-20 mm. broad : capsules twice as long as the 
calyx : seeds rough. [L. trachyspermum A. Gray. ] 
In ponds, Delaware and Maryland to Florida and Texas. Spring and summer. 
Order 6. ASCLEPIADALES. 
Herbs, shrubs or trees, commonly with a milky juice. Leaves alternate or 
opposite: blades entire. Inflorescence cymose, sometimes umbellate. Calyx of 
usually 5 partially united sepals. Corolla of usually 5 partially united petals, 
Androecium of 5 distinct or monadelphous stamens, partially adnate to the co- 
rolla in ASCLEPIADACEAE and accompanied by a 5-lobed crown. Pollen granu- 
lar or in waxy masses. Gynoecium of usually 2 carpels sometimes only united 
at the apex. Stigma terminal. Fruit a pair of follicles, or drupaceous. 
Styles united : stamens distinct: pollen loosely granular. Fam. 1. APOCYNACEAE. 
Styles distinct: stamens usually monadelphous: pollen united into waxy 
masses, or the grains in groups of 4. Fam. 2, ASCLEPIADACEAE. 
FAMILY 1. APOCYNACEAE Lindl. DoGBANE FAMILY. 
Perennial herbs, vines, shrubs or trees, mostly with a milky acrid juice. 
Leaves alternate or opposite, without stipules: blades simple. Flowers perfect, 
regular. Calyx of 5 persistent sepals imbricated in the bud. Corolla of 5 par- 
tially united petals, the lobes convolute in the bud. Androecium of 5 stamens 
alternating with the corolla-lobes. Filaments partially adnate to the corolla- 
tube. Anthers 2-celled. Pollen-grains simple. Gynoecium of two distinct car- 
pels or 2 united carpels. Ovary superior, 1-celled with 2 parietal placentae, or 
2-celled. Styles united. Stigmas simple. Ovules anatropous or amphitropous. 
Fruit usually of 2 follicles or drupes. Seed often appendaged. Endosperm 
fleshy. Embryo with straight cotyledons. 
Anthers unappendaged at the base, not connected with the stigma: corolla-lobes sinistrorsely convolute. 
it drupaceous: shrubs or trees. 
Corolla salverform, relatively smal! ; lobes equilateral, shorter than the bs E 
. VALLESIA. 
