LYTHRACEAE 825 
13. Rhexia aristósa Britton. Stems erect, 2-6 dm. tall, 4-angled, glabrous, some- 
times branching above, sometimes spongy at the base, the branches erect or strongly ascend- 
ing: leaf-blades thickish, linear or linear-lanceolate, or sometimes linear-oblong, 1-3 em. 
long, obtusish or acute at the apex, distantly bristly serrulate, sessile, glabrous or with a 
few scattered hairs above: flowers short-pedicelled : hypanthium bristly, or the tube gla- 
brate in age: sepals linear or linear-lanceolate, acuminate : petals magenta-red, 12-20 mm. 
long, awn-tipped : anthers linear, minutely spurred : capsules subglobose, 6 mm. long, longer 
than the neck of the hypanthium. 
In sandy swamps and pine lands, New Jersey to South Carolina. Summer. 
14. Rhexia parviflóra Chapm. Stems erect, less than 3 dm. tall, 4-angled, usually 
branched at the base and above, sparingly pubescent : leaf-blades oblong, elliptic or nearly 
oval, 1-2 cm. long, acute, bristly serrulate, short-petioled : cymes few-flowered : hypan- 
thium nearly glabrous at maturity : petals white, less than 10 mm. long, often awn-tipped : 
anthers narrow, nearly straight, appendaged, fully as long as the filaments : capsules sub- 
globose, about 3 mm. in diameter: mature hypanthium with a broad neck much shorter 
than the diameter of the body. 
In shallow ponds, Apalachicola, Florida. Summer. 
FAMILY 2. LYTHRACEAE Lindl. LOOSESTRIFE FAMILY. 
Herbs, shrubs, or often trees in the tropics, with firm or succulent tissues. 
Leaves mostly opposite: blades usually entire, sometimes auricled at the base. 
Flowers perfect, solitary or clustered in the axils, or in axillary cymes. Hypan- 
thium enclosing the ovary, but free. Calyx of 4-5 sepals, commonly accom- 
panied by accessory teeth. Corolla of 4-5 petals, or wanting. Androecium of 
few or many stamens in 1 or several series. Filaments mostly filiform : anthers 
versatile. Gynoecium compound. Ovary 2-6-celled, or rarely 1-celled. Styles 
united. Stigmas entire or rarely 2-lobed. Ovules numerous, or rarely few, 
anatropous. Fruit a thin-walled or firm capsule enclosed in the hypanthium, 
Sometimes indehiscent. Seeds variously marked or roughened. Embryo 
straight. 
Ss ee campanulate or turbinate, becoming hemispheric or globose. 
rps, 
Flowers inconspicuous. 
Petals wanting: capsules indehiscent. 1. DIDIPLIS. 
Petals 4: capsules ehiscent, sometimes irregularly so. 
Capsules bursting irregularly. 2. AMMANNIA. 
Capsules septicidally dehiscent. 3. RoTALA. 
Flowers conspicuous. 4. HEMIA. 
Shrubs or trees. 
Flowers in axillary cymes : aquatie shrubs. 5. DECODON. 
Flowers in terminal panicles: terrestrial shrubs or trees. 6. LAGERSTROEMIA. 
Hypanthium elongated, cylindrie or tubular. 
owers regular: hypanthium symmetrical. 7. LvTHRUM. 
Flowers irregular: hypanthium oblique. 8. PARSONSIA. 
1. DÍDIPLIS Raf. 
Flaccid aquatic or swamp herbs, resembling species of Callitriche. Stems elongated, 
4-angled. Leaves opposite: blades narrow, entire, pellucid. Flowers inconspicuous, ses- 
sile and solitary in the axils. Hypanthium prismatic-campanulate, 4-angled. Sepals 4, 
without accessory teeth. Petals none. Stamens 2-4, mostly 4: filaments very short. 
Ovary 2-celled : style very short: stigma slightly 2-lobed. Capsule subglobose, 2-celled, 
opening irregularly. Seeds minute. Testa membranous. Embryo clavate. 
1. Didiplis diándra (Nutt.) Wood. Stems flaccid, submerged or creeping on mud, 
1-3 dm. long, glabrous: leaves of two kinds, the submersed thin; blades linear to linear- 
lanceolate, acute or acuminate, the emersed ones thicker in texture ; blades linear to linear- 
Spatulate, often obtuse, all 1-2 cm. long: flowers inconspicuous: hypanthium campanu- 
late, angled, about 1 mm. high: petals none : capsule urn-shaped, about 1 imm. in diameter. 
D. linearis Raf. ] 
fall ponds or on wet shores, Minnesota to North Carolina, Florida, Texas and Mexico. Spring to 
: ER PURSLANE. 
2. AMMÁNNIA L. 
Annual, leathery-succulent herbs. Stems usually 4-angled. Leaves opposite: blades 
entire, often auricled at the base. Flowers inconspicuous, solitary or clustered (cymose) in 
