STANDLEY TREES AND SHRUBS OF MEXICO. 1099 



The fruit is often eaten by people, and it is a favorite food of bear. It is 

 often sold in the markets. Both the fruit and leaves are reputed to have 

 astringent and diuretic properties, and they are employed as a remedy for 

 dropsy, bronchitis, venereal diseases, and other affections. 



6. ARBUTTJS L. Sp. PI. 395. 1753. 



Shrubs or trees, the bark smooth, thin, peeling off in sheets ; leaves alternate, 

 persistent, petiolate, entire or serrate ; flovrers w^hite or pink, in terminal 

 panicles ; calyx o-lobate ; corolla urceolate, with 5 small lobes ; stamens 10, 

 the anthers 2-awned ; fruit baccate, globose, granular, 5-celled. 



The Mexican plants of this genus are extremely variable and seem not to 

 possess a single constant character. It appears probable that ultimately all 

 of them will have to be considered mere forms of .1. xalapensis. No confidence 

 can be placed in the characters used in the following key. Of the species 

 listed, the one most clearly distinct from A. xalapensis is A. glandulosa, but 

 even the chara'cters by which it can be recognized are far from constant. 



Arbutus unedo L., a European species, has been erroneously reported in 

 certain Mexican publications. 



Petioles glandular-hirsute 1. A. glandulosa. 



Petioles glabrous or tomentose. 

 Ovary glabrous. 



Leaves soon glabrous beneath 2. A. arizonica. 



Leaves persistently tomentose beneath. 



Pubescence of the inflorescence eglandular 3. A. laurina. 



Pubescence of the inflorescence partly of gland-tipped hairs. 



Calyx glabrous 4. A. peninsularis. 



Calyx tomentulose 5. A. donnell-smithii. 



Ovary pubescent. 



Calyx lobes triangular, acute or acuminate 6. A. spinulosa. 



Calyx lobes broadly ovate or orbicular, obtuse 7. A. xalapensis. 



1. Arbutus glandulosa Mart. & Gal. Bull. Acad. Brux. 9^: 533. 1842. 

 Arbutus villosa Willd. ; Klotzsch, Linnaea 24: 72. 1851. 



Chihuahua to Veracruz, Chiapas, and Sinaloa; type from Ejutla, Oaxaca. 



Shrub or tree, 3 to 8 meters high, with red-brown bark ; leaves oblong to ovate 

 or oval, 4 to 13 cm. long, acute or obtuse, acute to cordate at base, entire 

 or serrate, tomentose or glabrate beneath ; panicles 2 to 10 cm. long, glandular- 

 hirsute; corolla 8 mm. long. " Nuzu-ndu " (Oaxaca, Seler) ; "madrono" 

 (Oaxaca, Sinaloa); " aile " (Sinaloa). 



2. Arbutus arizonica (A. Gray) Sarg, Gard. & For. 4: 317. 1891. 

 Arbutus xalapensis arizonica A. Gray, Syn. Fl. ed. 2. 2': 396. 1886. 

 Chihuahua and Sonora to Jalisco and San Luis Potosl. Southern Arizona 



(type locality) and New Mexico. 



Tree, 5 to 15 meters high, the trunk sometimes 60 cm. in diameter ; bark thin, 

 peeling off in red-brown papery sheets; leaves long-petiolate, oblong to ovate, 

 4 to 10 cm. long, obtuse or acute, pale beneath and glabrous, at least in age, 

 usually entire ;^corolla white or pink, 8 mm. long ; fruit 6 to 8 mm. in diameter, 

 orange-red; wood soft, close-grained, reddish brown, its specific gravity about 

 0.71. "Madrono" (Chihuahua). 



3. Arbutus laurina Mart. & Gal. Bull. Acad. Brux. Qi; 535. 1842. 

 Type from Yavezia, Oaxaca. 



Tree with red-brown branches ; leaves oblong or ovate-oblong, 3 to 9 cm. long, 

 obtuse or acutish, narrowed or rounded at base, serrate, pubescent beneath; 

 panicles 4 to 8 cm. long ; corolla 6 to 7 mm. long. 



