STANDLEY — TREES AND SHRUBS OF MEXICO. 35 



Style undivided. 



Ovary 1-ceIled GESNERIACEAE. 



Ovary 2-celled. 



Corolla valvate or plicate in bud; fruit often baccate; 



plants often armed with spines SOLANACEAE. 



Corolla imbricate in bud ; friiit a capsule with longitudinal 

 dehiscence ; plants unarmed. 



SCROPHULARIACEAE. 

 CC. Ovary simple and of 3 or more cells, or the ovaries 3 or more and 

 distinct. 

 Ovules 1 or 2 in each cell. 

 Leaves opposite or verticillate. 



Cells of the ovary 3 ; stigmas 3 ; fi'uit a capsule. 



POLEMONIACEAE. 

 Cells of the ovary 4 or 5 ; stigmas 1, 2, 4, or .5 ; fruit indehiscent 

 or divided into nutlets. Leaves simple. 



Ovary entire. Stigmas 3, rarely 5 VERBENACEAE. 



Ovary 4-parted. 



Stamens 4 ; stigmas 2 or rarely 1 ; corolla bilabiate. 



MENTHACEAE. 



Stamens 5 ; stigma 1 ; corolla regular BORAGINACEAE, 



Leaves alternate. 

 Anthers basifixed, opening laterally or apically. leaves entire. 



DIOSPYRACEAE. 

 Anthers dorsifixed, or basifixed and opening internally. 



Corolla united only at the base AQTJIEOIilACEAE. 



Corolla with a conspicuous tube. 



Flowers mostly in 1-sided cymes ; fruit not a capsule. 



BORAGINACEAE. 

 Flowers not in 1-sided cymes ; fruit a capsule. 



CONVOLVULACEAE. 

 Ovules 3 or more in each cell. 



Corolla valvate or plicate in bud ; stamens inserted on the corolla; 

 calyx more or less united ; plants often armed with spines. 



SOLANACEAE. 

 Corolla imbricate or contorted ; stamens often free from the corolla ; 

 calyx segments often distinct or nearly so ; plants unarmed. 

 Anthers dehiscent by longitudinal slits ; ovary 3-celled. 



POLEMONIACEAE.. 

 Anthers dehiscent by terminal pores ; ovary with 2 or 4 or more 



cells ERICACEAE. 



liB. Perfect stamens 2 to 4. fewer than the corolla lobes, or if of the same 

 number the stamens and lobes each 2 ; corolla nearly always irregular. 

 Ovules 1 or 2, rarely 3 or 4, in each cell. 

 Ovules 1 in each cell. 



Ovary entire or obscurely 4-lobate VERBENACEAE. 



Ovary 4-parted or deeply 4-lobate MENTHACEAE. 



Ovules 2 to 4 in each cell. 



Ovary 4 or 5-celled ; leaves with translucent glands RUTACEAE. 



Ovary 2-celled ; leaves without translucent glands. 



Stamens 2, regularly alternate with the cells of the ovary. Flowers 



regular; leaves opposite OLEACEAE. 



Stamens 4, or if 2 not alternate with the cells of the ovary. 

 Ovules 2 and collateral ; fruit indehiscent or septicidal. 



VERBENACEAE 



