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. — Mont.; Mex.; 

 Brazil. Plain. Jl-S. 



2. ROTALA L. 



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

 narrow, entire. Flowers perfect, usually soUtary in the axils. HjTjanthium 

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

 usually 4. Stamens 4; filaments short. Ovary subglobose, 4-celled; stj'les very 

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

 4-valved. 



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

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

 sohtary in the axils; cal}^ 3—4 mm. long; lobes acuminate; petals minute; cap- 

 sule elhpsoid. Wet places: Mass.— Fla.— Tex.— Xeb.—Cahf.— Ida.— Wash.; W. 

 Ind. and Mex. Jl-S. 



3. LYTHRUM L. Loosestrife. 



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

 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 2-celled; 

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

 2-valved or bursting irregidarlj*. 



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 solitary' in the upper 

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

 ribbed. Low ground: Ont,— Mass.— D.C.—Tex'.—Wj-o.— B.C. Plaiii. Je-Au. 



Family 91. ONAGRACEAE. EvExiNG-PRiMaosE Fa^mily. 



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

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

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

 usually 4, convolute in the bud, rarely wanting. Stamens as many or t^-ice 

 as man}' as the sepals. Gynoecium of 1-6, usually 4, united carpels. Ovary 

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



Flowers 4-merous. 



Fruit a many-seeded capsule, opening by valves. 

 Seeds with a tuft of silky hairs. 



Hj-panthium not prolongea beyond the o%'ary; flowers large. 



1. Chamaexekion. 

 Hj-panthium somewhat prolonged beyond the ovary. 



Hypanthium-tube cjlindric, not inflated above the ovary, without scales 

 within; flowers neither showy nor scarlet. 

 Flowers regular; stamens and style not declined; petals purplish, pink 



or white. In ours yellow only in one species. 2. EPiLOBruii. 

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

 ish. 3. CORDVLOPHORUM. 



H}-panthiuni-tube inflated above the ovary, bearing 8 scales within; flow- 

 ers irregular, showj- scarlet. 4. Zauschxerl\. 

 Seeds without a tuft of silkj- hairs, naked or tuberculate. 



Hj-panthium not produced beyond the ovary; flowers minute. 



Stamens 8; sepals deciduous; capsule linear. 5. Gayophttum. 



Stamens 4; sepals persistent; capstile obovoid or turbinate. 



6. ISN.UIDIA. 



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

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



Calyx-lobes erect; petals minute, clawless; capsule membranous. 



7. BOISDUVALLL\. 



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



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



8. CLARKJLi. 



