STANDLEY TREES AND SHRUBS OF MEXICO. 1047 



truncate, lobed, or calyptriform ; petals as many as the calyx lobes, inserted 

 on the limb of the calyx; stamens as many or twice as many as the petals; 

 style simple, the stigma capitate or punctiform ; fruit baccate or capsular, 2 to 

 many-celled. 



One of the largest families of American plants, in Mexico confined chiefly 

 to the truly tropical, and generally humid portions of the southern states. 

 Since nearly all the Mexican representatives of the family are woody, it has 

 seemed advisable to include in the present treatment the herbaceous species 

 as well. 



One class of terms used in describing the nervation of the leaves in this 

 family shoxild be explained here : Three-nerved or .5-nerved leaves are those in 

 which all the nerves arise from the base of the blade ; triplinerved or qnintupli- 

 nerved leaves are those in which the lateral nerves have their origin above the 

 base of the blade. 



Fruit capsular ; stamens usually unequal. 

 Capsule 3-winged, dilated at apex 13. TRIOLENA. 



Capsule terete or angulate, acute or obtuse at apex. 



Connective of the anther usually long-produced below the base of the 

 anther. 

 Seeds oblong or ovoid. 



Anthers rostrate 1. RHYNCHANTHERA, 



Anthers erostrate 2. CENTRADENIA. 



Seeds cochleate. 



Stamens very unequal ; connective of the larger anthers with 2 elon- 

 gate appendages. 

 Lobes of the calyx much shorter than the tube. 



3. ARTHROST^EMMA, 

 Lobes equaling the tube or nearly so. 



Connective of the smaller anthers bilobate anteriorly ; connec- 

 tive of the larger anthers bifid or with 2 long spurs anteriorly. 



4. ACISANTHERA. 

 Connective of the smaller anthers not bilobate, that of the larger 

 anthers with an elongate bifid appendage. 



5. HETEROCENTRON. 

 Stamens subequal, the anthers all of about the same size, the con- 

 nective merely biauriculate or bituberculate. 



Ovary glabrous at apex , 6. ACIOTIS. 



Ovary setose at apex. 

 Calyx tube with 8 very broad, thick tuberculate-setose ribs. 



7. SCHWACKAEA. 

 Calyx tube with very slender nervelike ribs. 



Calyx lobes alternating with penicillate-stellate bristles. 



8. PTEROLEPIS. 

 Calyx lobes without intermediate bristles __9. TIBOUCHINA. 

 Connective of the anther not conspicuously produced below the base of 

 the anther. 



Seeds cochleate 10. MONOCHAETUM. 



Seeds ovoid or fusiform. 

 Plants scandent ; calyx limb shallowly 5-lobate__ll. ADELOBOTRYS. 



Plants erect; calyx limb circumscissile 12, CALYPTREIiLA. 



Fruit baccate or coriaceous and rupturing irregularly ; stamens equal or 

 nearly so. 

 Leaves pinnate-nerved 24. MOURIRIA. 



