STANDLEY TEEES AND SHRUBS OF MEXICO. 309 



Petals 3 to 4 mm. long. 

 Tomentum of the lower surface of the leaves of similar, very closely 



appressed hairs 2. D. pringlei. 



Tomentum of unequal, loose, and spreading haii'S 3. D. occidentalis. 



1. Deutzia mexicana Hemsl. Diag. PI. Mex. 9. 1878. 

 Neodeutzia mexicana Small, N. Amer. Fl. 22: 162. 1905. 

 Veracruz ; type from Orizaba. 



Shrub, 2 to 5 meters high ; leaves ovate, 2.5 to 5 cm. long, white-pubescent 

 beneath. 



2. Deutzia pringlei C. Schneid. Mitt. Deutsch. Dendr. Ges. 1904: 186. 1904. 

 Neodeutzia ovalis Small, N. Amer. Fl. 22: 162. 1905. 



Neodeutzia pringlei Small & Rydb. N. Amer. Fl. 22: 555. 1918. 

 Known only from the type locality, San Jos6 Pass, San Luis Potosl. 

 Shrub, 3 meters high ; leaves oval or oblong, 1.5 to 2.5 cm. long, rounded at 

 apex, green on the upper surface, white beneath. 



3. Deutzia occidentalis Standi. Proc. Biol. Soc. Washington 31: 134. 1918. 

 Neodeutzia occidentalis Rydb. N. Amer. Fl. 22: 555. 1918. 



Puebla and Oaxaca ; type from Barranca del Oro, Puebla. 

 Shrub, sometimes 4.5 meters high; leaves ovate-orbicular or ovate, 2.8 to 4.5 

 cm. long. 



3. PHILADELPHUS L. Sp. PL 470. 1753. 

 Shrubs ; leaves deciduous or somewhat persistent, entire or shallowly serrate ; 

 flowers white, large and showy. 



Patoni gives the local name of one of the Durango species as " mirto." 

 Many of the species which are natives of Asia and the United States are culti- 

 vated for their showy, often fragrant flowers. The native species, and perhaps 

 some of the foreign ones, are grown in Mexican gardens. The usual English 

 names for the plants are " syringa " ^ and " mock orange," the latter name prob- 

 ably given because of the sweet odor of the flowers in some species. Phila- 

 delphus coronarius L., an Old World species, has been reported from Mexican 

 gardens, and may very likely be cultivated there. The name was applied by 

 Sesse and Mocino ^ to a native species. 



Petals acute; stamens about 15 1. P. mearnsii. 



Petals rounded or refuse at apex ; stamens 25 to 60. 

 Styles and free portion of the ovary glabrous. 

 Leaves pilose on the upper surface with spreading hairs. 



Style evident ; bark of older stems yellowish 2. P. pumilus. 



Style nearly obsolete ; bark of older stems dark gray. 



3. P. serpyllifolius. 

 Leaves strigose on both surfaces. 



Bark of the previous year's branches not exfoliating. 



4. P. asperifolius. 



Bark of the previous year's branches exfoliating 5. P. madrensis. 



Styles or free part of the ovary or both more or less hairy. 

 Inflorescence 1 to 3-flowered ; petals more or less hairy. 



Calyx strigose ; petals without a reddish spot at base 6. P. mexicanus. 



Calyx densely white-sericeous ; petals sometimes with a reddish spot 

 at base 7. P. coulteri. 



* This name is also the Latin generic name of the lilac, \Syringa vulgaris L., of 

 the family Oleaceae. 



' PI. Nov. Hisp. 82. 1887. 



