LOOSESTRIFE FAMILY 583 



than half as long as the capsule. A. latifolia T. & G., not L. (?) A. alcalina 

 Blankinship. Swamps and wet places; Ind. — Fla. — Tex. — Wyo. — ISIont.; Mex.; 

 Brazil. Plain. Jl-S. 



2. ROTALA L. 



Annual or biennial swamp herbs, with 4-angled stems. Leaves ojiposite, 

 narrow, entire. Flowers perfect, usually solitary in the axils. Hypanthium 

 campanulate, becoming subglobose in fruit. Sepals 4, very small. Petals 

 usually 4. Stamens 4; filaments short. Ovary subglobose, 4-oolled; styles very 

 short; stigma entire or nearly so. Capsule 4-celled, subglobose, septicidally 

 4-valved. 



1. R. ramosior (L.) Koehne. A glabrous annual, 5-25 cm. high; leaves 

 oblong or linear-oblong, 1-3 cm. long, obtuse, acute at the base; flowers usually 

 sohtary in the axils; calyx 3-4 mm. long; lobes acuminate; petals minute; cap- 

 sule ellipsoid. Wet places: Mass.— Fla.— Tex.— Xeb.— Calif.— Ida.— Wash.; W. 



Ind. and Mex. Jl-S. 



3. LYTHRUM L. Loosestrife. 



Herbs or shrubs, with angled stem; ours perennial herbs. Flowers solitary 

 in the axils, or in spikes or racemes. Hypanthium cylindric, ribbed or grooved. 

 Sepals 4-6, accompanied with as many accessory teeth. Petals 4-6, obovate or 

 oblanceolate. Stamens 8-12, in one series; filament filiform. Ovary 2jcelled; 

 stigma capitate. Capsule membranous, 2-celled, or becoming 1-celled, septicidally 

 2-valved or bursting irregularly. 



1. L. alatum Pursh. Perennial; stem glabrous, 3-12 dm. high, 4-angled or 

 -winged; leaves sessile, alternate or the lowest opposite, lanceolate or oblong, 

 rounded at the base, acute at the apex, 2-3 cm. long; flowers sohtary in the upper 

 axils; petals deep purple, ascending; disk fleshy; calyx 5-6 mm. long in fruit, 

 ribbed. Low ground: Ont.— IMass.— D.C.— Tex.— Wyo.— B.C. Plain, Je-Au. 



Family 91, ONAGRACEAE, Evening-Primrose Family, 



Herbs, or rarely shrubs, with simple alternate or opposite leaves. Flow- 

 ers perfect, axillary or in terminal racemes. Hypanthium often elongate, 

 enclosing and adnate to the ovary. Sepals 2-6, usually 4. Petals 2-9, 

 usually 4, convolute in the bud, rarely wanting. Stamens as many or twice 

 as many as the sepals. Gynoecium of 1-6, usually 4, united carpels. Ovary 

 1-6-celled, inferior; styles united. Fruit capsular or nut-like. 



Flowers 4-meroiis. 



Fruit a many-seeded capsule, opening by valves. 



Seeds with a tuft of silky hairs. ^ , 



Hypanthiiim not prolonged beyond the ovary; flowers ^^f^-^^^^j^^^-Ej^j^^j^^ 



H\-panthium somewhat prolonged beyond the ovar>-. _,-^t,^„* .^^i^ 



Hypanthium-tube c>Undric. not inflated above the ovary, without scales 



within; flowers neither showy nor scarlet. ,. i, • i 



Flowers regular; stamens and style not dechned; petals purplish, pmk 



or white, in ours yeUow only in one species. 2. Epilobium. 

 Flowers irregular; stamens and style somewhat declined; petals yellow- 



j oi, 3 » CORDYIXJPHORtTil - 



Hypanthium-tube inflated above the ovary, bearing 8 scales mtMn ; flow- 

 ers irregular, showy scarlet. 4. Zauschnerlv. 

 Seeds without a tuft of silky hairs, naked or tuberculate. ^ 



Hypanthium not produced beyond the ovarj-; flowers ^^^^^e. 



Stamens 8; sepals deciduous; capsule hnear. 5. (jtAYOphiilm. 



Stamens 4; sepals persistent; capsule obovoid or turbinate. 



H^-panthium prolonged beyond the ovary into a cylindric or funnelform tube. 

 Anthers attached near the base, erect; petals never yeUow. 



Calyx-iobes erect; petals minute, clawless; capsule membranoi^. 



Calyx-lobes reflexed; petals showy, clawed; capsule coriaceous. 



Fertile stamens 4, the alternate ones rudimentary; petals 3-loDea. 



8. CLARKIA. 



