STANDLEY TREES AND SHRUBS OF MEXICO. 1129 



DOUBTFUL SPECIES. 



DiosPYROS VELUTiNA Hiem, Trans. Cambridge Phil. Soc. 12: 200. 1873. Bnsed 

 upon material from Brazil, but one Mexican specimen is reported. 



136. STYKACACEAE. Storax Family. 

 Reference : Perkins in Engl. Pflanzenreich IV. 241. 1907. 



1. STYRAX L. Sp. PI. 444. 1753. 



Shrubs or small, trees, with stellate pubescence; leaves alternate, estipulate, 

 entire or remotely serrate; flowers perfect, white, in short, axillary or 

 terminal, simple or branched racemes ; calyx cupuliform, truncate or 5-denticu- 

 late ; petals 5, short-connate ; stamens 10, inserted at base of the corolla ; 

 style simple, the stigma capitate; fruit globose, dry or nearly so, 1-seeded, 

 usually indehiscent. 



Styrax 'benzoin Dryand., an Old World species, furnishes the resin known 

 as benzoin, which is an official drug, and is employed also in perfumes and 

 incense. 



Corolla lobes imbricate ; leaves less than twice as long as broad. 



Leaves densely stellate-pubescent on the upper surface 1. S. jaliscanus. 



Leaves glabrous on the upper surface or nearly so. 



Leaves densely stellate-tomentulose beneath 2. S. pilosus. 



Leaves glabrous beneath, sometimes barbate in the axils of the nerves. 



3. S. glabrescens. 

 Corolla lobes valvate; leaves more than twice as long as broad. 

 Leaves covered beneath with coarse spreading stellate hairs, the pubescence 



velutinous 4. S. argenteus. 



Leaves covered beneath with a minute, very close, stellate tomentum. 



Flowers 1.5 cm. long 5. S. ramirezii. 



Flowers about 1 cm. long. 



Calyx about 2 mm. long 6. S. cyathocalyx. 



Calyx about 4 mm. long 7. S. polyneurus. 



1. Styrax jaliscanus S. Wats. Proc. Amer. Acad. 26: 144. 1891. 



Styrax officinalis jali.scanus Perkins in Engl. Pflanzenreich IV. 241: 82. 

 1907. 



Jalisco; type from Sierra de San Esteban. 



Shrub, about a meter high ; leaves subsessile, rounded-ovate to oblong-ovate, 

 4 to 10 cm. long, abruptly short-acuminate, entire, densely Avhitish-tomentose 

 beneath ; racemes 1 to 5-flowered, short ; calyx evidently dentate ; flowers 1.5 

 to 2 cm. long ; fruit 8 to 12 mm. in diameter. 



This is closely related to S. officinalis L., and perhaps not sufficiently dis- 

 tinct from that species of the Mediterranean region. The latter species yields 

 a gum which was employed by the Egyptians as a perfume, and in recent times 

 has been employed in medicine as " stoi'ax oflScinalis." 



2. Styrax pilosus (Perkins) Standi. 



Styrax glabrescens pilosiis Perkins in Engl. Pflanzenreich IV. 241: 72. 1907. 



Type from Chinantla and Rinc6n, Oaxaca, altitude 900 meters. 



Leaves slender-petiolate, elliptic-oblong or elliptic, G to 10 cm. long, short- 

 acuminate, glabrous above or when young with minute scattered stellate hairs, 

 densely and minutely tomentulose beneath ; flowers sweet-scented ; calyx 4 mm. 

 long, subentire, minutely grayish-tomentulose. 



