FLORA OF THE DISTRICT OF COLUMBIA. 51 



Plants herbaceous. 

 Ovaries more than 1, or, if 1, deeply lobed. 

 Ovary deeply 4-lobed. 

 Leaves alternate; corolla regular (irregular in Echium) ; steins terete. 



BORAGINACEAE (p. 237). 

 Leaves opposite; corolla usually 2-lipped; stems 4-sided. 



MENTHACEAE (p. 239). 

 Ovaries 2, or solitary and 2-horned. 



Stamens united. ASCLEPIADACEAE (p. 231) 



Stamens distinct. 



Ovary 2-horned; stipules present LOGANIACEAE (p. 228). 



Ovaries 2; stipules none APOCYNACEAE (p. 229). 



Ovary 1, not deeply lobed. 

 Corolla irregular; anther-bearing stamens 2 or 4 (except Echium and Ver 

 bascum with 5). 

 Ovules solitary in the 1-4 cells. 



Ovary 1-celled; fruit reflexed PHRYMACEAE (p. 256). 



Ovary 2-4-celled; fruit not reflexed VERBENACEAE (p. 239). 



Ovules 2 to many in each cell. 

 Ovary 1-celled. 

 Plants terrestrial, without chlorophyll; stamens 4. 



OROBANCHACEAE (p. 254). 

 Plants aquatic or growing on mud, chlorophyll-bearing; stamens 2. 



PINGUICULACEAE (p. 255). 

 Ovary 2-celled. 

 Capsule elastically dehiscent; seeds few, borne on hooklike processes 



of the placentae ACANTHACEAE (p. 255). 



Capsule not elastically dehiscent; seeds numerous, not borne on 



hooks SCROPHULARIACEAE (p. 248). 



< 'orolla regular. 



Stamens fewer than 1 he corolla lobes. 

 Stamens with anthers 4. 



Ovary 2-celled; cells several-seeded Ruellia (p. 256). 



Ovary 2-4-celled; cells 1-seeded: VERBENACEAE (p. 239). 



Stamens with anthers 2. 



Leaves basal; corolla scarious PLANTAGINACEAE (p. 256). 



Leaves arranged along the stem ; corolla not scarious .Veronica (p. 252) . 

 Stamens as many as the corolla lobes. 

 Ovary 1-celled. 



Leaves entire, opposite GENTIANACEAE (p. 228). 



Leaves toothed, lobed, or compound, alternate. 



HYDROPHYLLACEAE (p. 236). 

 Ovary 2^1-celled. 



Plants leafless twining parasites, without chlorophyll. 



CUSCTJTACEAE (p. 234). 

 Plants with chlorophyll, not parasitic. 

 Ovary 4-celled; fruit separating into 4 nutlets; plants rough-hairy. 



Heliotropium (p. 237). 

 Ovary 2-3-celled ; fruit a capsule or berry ; plants glabrous or pubes- 

 cent but not rough-hairy. 

 Ovary and capsule 3-celled, the style 3-lobed. 



POLEMONIACEAE (p. 235). 

 Ovary and capsule or berry 2-celled. 



Seeds few, mostlv 4; fruit a capsule; plants usually twining. 



CONVOLVULACEAE (p. 233). 



Seeds many; fruit a capsule or berry; plants not twining 



(except Solarium dulcamara) . . . .SOLANACEAE (p. 247). 



