FLORA OF THE DISTRICT OF COLUMBIA. 31 



Sepals more than 2, usually persistent; plants with colorless juice. 

 Petals and sepals each 4, regular; petals yellow, white, or pink; fruit a 2-celled 

 pod with several or numerous seeds. Leaves once pinnate. 



BRASSICACEAE (p. 163). 



Petals 5 or none; sepals usually 5, sometimes 4; petals yellow, red, or white; 



sepals and petals sometimes spurred; fruit a 1-seeded achene, or each fruit 



composed of several pods RANUNCULACEAE (p. 156). 



D. 



Plants climbing, often with tendrils; leaves simple. 



Plants with tendrils. 

 Leaves 5-9-ribbed, usually entire; flowers in umbels. Fruit a bluish black berry 



with 2-6 seeds; stipules none SMILACACEAE (p. 124). 



Leaves not ribbed, lobed or toothed; flowers not in umbels. 

 Stipules present; petals distinct; flowers 2.5-5 cm. broad, solitary, greenish yellow, 



PASSIFLORACEAE (p. 211). 

 Stipules none; petals united; flowers about 1 cm. broad, mostly in racemes or 



corymbs CUCURBITACEAE (p. 262). 



Plants without tendrils. 

 Leaves peltate, the petiole attached on the under side of the blade near the margin, 

 the blades angled or lobed; fruit juicy, 1-seeded. Flowers very small, in axil- 

 lary panicles .• MENISPERMACEAE (p. 161). 



Leaves not peltate; fruit not juicy. 

 Leaves, at least the lowest ones, opposite or whorled. 

 Leaves entire; fruit not an achene, with 3 or many seeds. 

 Plants with milky juice; petals 5, united, whitish or dark purple; fruit of 

 large pods, containing many seeds, these bearing a tuft of silky hairs. 



ASCLEPIADACEAE (p. 231). 

 Plants with colorless juice; petals 3, distinct, greenish yellow; fruit a 3-winged 



capsule, the seeds not hairy DIOSCOREACEAE (p. 125). 



Leaves toothed or lobed; fruit an achene. 

 Blades of the leaves, at least most of them, deeply lobed, rough; flowers dioe- 

 cious, green, in catkins or panicles Humulus (p. 142). 



Blades of the leaves merely toothed, glabrous; flowers perfect, in small heads, 



each head surrounded by 4 bracts Mikania (p. 275). 



Leaves alternate. 

 Leaves with sheathing stipules; corolla none; fruit an achene. 



POLYGONACEAE (p. 144). 

 Leaves without stipules; corolla gamopetalous, showy; fruit a capsule. 



CONVOLVULACEAE (p. 233). 



Plants without green coloring; leaves reduced to scales; fruit a capsule. 



Stems twining, parasitic upon the stems of other plants, bright yellow or orange, slender 



Corolla regular, gamopetalous CIJSCUTACEAE (p. 234). 



Stems erect, the plants growing in the ground, not bright yellow or orange, stout. 

 Flowers regular or nearly so, the petals distinct. Plants glabrous or pubescent. 



MONOTROPACEAE (p. 221). 

 Flowers very irregular. 



Plants glabrous; petals and sepals each 3, distinct ORCHIDACEAE (p. 127). 



Plants pubescent; corolla of united petals OROBANCHACEAE (p. 254). 



