STANDLEY TREES AND SHRUBS OF MEXICO. 1058 



Stems sparsely branched or simple, appressed-setose ; leaves lance-oblong, 1 

 to 3 cm. long, acute, setose ; calyx tube 3 mm. long ; petals pink, 5 to 6 mm. 

 long. 



2. Pterolepis trichotoma (Rottb.) Cogn. in Mart. Fl. Bras. 143; 261. 1885. 

 Rhexia trichotoma Rottb. Descr. PI. Surin. 9. pi. 5. 1776. 



Rkexia ladanoides Rich, in Humb. & Bonpl. Monogr. Melast. 2: 72. pi. 27. 



1823. 

 Pterolepis ladanoides Triana, Trans. Linn. Soc. Bot. 28: 89. 1871. 

 Veracruz and perhaps elsewhere. Central and South America. 

 Stems herbaceous, 20 to 30 cm. high, appressed-setose; leaves lanceolate or 

 lance-oblong, 3 to 8 cm. long, short-petiolate ; petals pinlf, 8 to 10 mm. long. 



3. Pterolepis pumila (DC.) Cogn. in Mart. Fl. Bras. 14^: 263. 1885. 

 Osbeckia pumila DC. Prodr. 3: 141. 1828. 



Reported from Oaxaca. Central and South America. 



Leaves short-petiolate or subsessile, lanceolate or oblong-lanceolate, 1.5 to 

 2.5 cm. long, setose-pilose ; petals pint:, 5 to 6 mm. long. 



9. TIBOUCHINA Aubl. PI. Guian. 445. 1775. 



Shrubs or rarely herbs ; leaves 3 or 5-nerved, entire or serrulate ; flowers 

 5-parted, solitary or in terminal panicles; calyx tube oblong or urceolate. the 

 lobes narrow, persistent or deciduous ; petals obovate ; stamens unequal or 

 subequal, the anthers similar, the connective produced below the cells but 

 sometimes very shortly so ; capsule 5-valvate. 



Calyx with gland-tipped hairs. 



Pubescence of the young branches widely spreading 1. T. purpusii. 



Pubescence of the young stems appressed. 

 Hairs on the upper surface of the leaf and on the stems long and slender. 



2. T. galeottiana. 



Hairs on the leaves and stems short, thickened at base 3. T. durangensis. 



Calyx with eglandular hairs. 



Connective of the larger anthers long-produced at the base (about 2 mm. 

 or more). 



Pubescence of the stems spreading 4. T. rufipilis. 



Pubescence of the stems appressed 5. T. mexicana. 



Connective very shortly produced (1 mm. or less). 

 Stamens equal in length or nearly so. 



Lobes of the calyx shorter than the tube 6. T. bourgaeana. 



Lobes equaling or longer than the tube. 

 Hairs of the stem short, closely appressed ; leaves serrulate. 



7. T. naudiniana. 

 Hairs of the stem long, ascending, not closely appressed ; leaves 



usually entire 8. T. longifolia. 



' Stamens very unequal. 



Hairs of the stem closely appressed 9. T. schiedeana. 



Hairs of the stem spreading or ascending, not appressed. 

 Lobes of the calyx equaling or longer than the tube. 



Calyx lobes linear 10. T. scabriuscula. 



Calyx lobes linear-spatulate 11. T. spathulata. 



Lobes shorter than the tube. 



Calyx tube 6 mm. long, the lobes 3 mm. long 12. T. ferrariana. 



Calyx tube 5 mm. long, the lobes 3 to 4 mm. long 13. T. monticola. 



