266 P ACEAE 
1. ZOSTERELLA Small. Aquatic plants with regularly leafy stems. 
Leaf-blades linear, sessile. Spadix 1-flowered. Perianth yellow, regular, the 
lobes narrow, nearly equ i Stamens 3, 
] h 
equal: anthers narrow, erect. Ovary 
3-celled: style jn CD —— un- 
der the stigma. Ovules numerous. Cap- 
sule many-seeded.—T'wo species of tem- 
perate and tropieal Ameriea 
1. Z. dubia (Jacq.) Small. Stem and 
on elongate: leaf-blades mainly 4- 
long: perianth lobes linear, 8— 
m. lon capsule 4-6 mm. Jong. 
[Heteranthera eae (Michx.) Vahl] 
(WAT ss.)—Still MI 
water, various cS Fla. to Tex., 
Ore, and Ont.—(W. I., Mez.)—Spr.— 
- 
sum sually ith the foliage 
submersed, but with the flowers extending above the water. On muddy shores 
the plant sometimes develops a short erect stem 
2. HETERANTHERA R. & P. Plants of muddy places, with rootstocks 
from which arise short branches bearing a cluster of leaves and a pedunele 
with a braet. Leaf-blades broad, long-petioled. Spadix l-few-flowered. Peri- 
anth white or blue, the calyx-lobes narrower than the corolla-lobes. Stamens 
others: anthers versatile. Ovary 3-celled: styles barely if at all thiekened 
under the stigma. Ovules numerous. Capsule many-seeded.—About 8 species, 
mostly natives of tropieal Ameriea.—MUD-PLANTAINS 
Leaf-blades longer than wide, obtuse at both ends : style glabrous. 1 
Leaf-blades wider than long, cordate at the base: style pubescent. 2. 
1. H. limosa (Sw.) Willd. Leaf-blades 
ovate to elliptic-ovate, 1-4 long: 
spadix E _erianth bine: tube 
m y 
reniformis. 
zi 
long. — Ditches, DNE Mar and mud, 
various provinces, Fla. to N. M., Colo., 
and Va.—(W. I., Mez., C. A., S. A.) 
2. H. reniformis R. & P.  Leaf- Es 
reniform or orbieular- reniform 
mostly 1 em. lo ong.— —Shallow water and 
mud, various provinces, Ga. to Tex., and 
Conn.— (W. I., Mez., C. A., S. A) 
| 3. PONTEDERIA L. Aquatic herbs. Leaf-blades narrow or broad, the 
basal on tapering petioles. Spadix many-flowered. Perianth 2-lipped, blue with 
a yellow spot on the upper lip, the lobes nearly equal. Anthers versatile. Ovary 
l-eelled. Fruit with tubercled or incised crests. Seed solitary.—About 8 species, 
natives of America.—PICKEREL-WEEDS. DoG-TONGUES. WAMPEES.)—Frequently 
ealled BLUE-FLAGS. 
