1088 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



127. CLETHRACEAE. Clethra Family. 

 1. CLETHRA L. 



Shrubs or trees ; leaves alternate, petiolate, entire or toothed ; flowers per- 

 fect, in terminal, simple or branched racemes; calyx 5-cleft, the lobes Imbri- 

 cate, persistent ; petals 5, white, imbricate, deciduous ; stamens 10, the anthers 

 sagittate, opening by apical pores : fruit a 3-lobed, loculicidally 3-valvate cap- 

 sule. 



Leaves glabrous beneath 1. C. suaveolens. 



Leaves finely or coarsely tomeutose beneath. 

 Pedicels shorter than the calyx, very stout. 



Leaves covered beneath with a minute, very close tomentuni. 



2. C. alcoceri. 



Leaves covered beneath with, a coarse loose tomentum 3. C. mexicana. 



Pedicels all or mostly as long as the calyx, comparatively slender. 

 Calyx 2.5 to 3 mm. long ; leaves with a fine close tomentum beneath. 



Pedicels mostly 7 to 12 mm. long 4. C. pringlei. 



Pedicels mostly 2 to 4 mm. long 5. C. macrophylla. 



Calyx 3 to 5 mm. long ; leaves with a coarse loose tomentum beneath. 



Leaves coarsely and sharply serrate 6. C. rosei. 



Leaves entire, undulate-dentate, or serrulate. 



Leaves oblong 7. C. hartwegi. 



Leaves mostly obovate 8. C. lanata. 



1. Clethra suaveolens Turcz. Bull. Soc. Nat. Moscou 362; 230. 1863. 

 Type from Chiapas, at an altitude of 2,100 meters. Guatemala. 

 Branches glabrous or nearly so; leaves mostly oblong, 6 to 12 cm. long, 



acute or acuminate, entire ; racemes 10 to 16 cm. long, the slender pedicels 3 to 

 8 mm. long; calyx tomentose, about 4 mm. long; petals 5 mm. long. 



2. Clethra alcoceri Greenm. Proc. Amer. Acad. 41: 240. 1905. 



Known only from the type locality, Trinidad Iron Works, Hidalgo, altitude 

 1,590 meters. 



Small tree, the branchlets brown-tomentulose ; leaves obovate-oblong or 

 elliptic-lanceolate, 10 to 14 cm. long, acute or short-acuminate, serrate, glabrate 

 above; racemes 10 to 20 cm. long, the pedicels 1 to 3 mm. long; calyx 3 mm. 

 long ; petals erose-fimbriate. 



3. Clethra mexicana DC. Prodr. 7: 590. 1839. 



Clethra obovata Hook. & Arn. Bot. Beechey Voy. 302. 1837. Not C. obovata 

 Ruiz & Pav. 1834. 



Clethra quercifolia Lindl. Bot. Reg. 28: pi. 2S. 1842. 



IKotcaleicskia scrrulata Turcz. Bull. Soc. Nat. Moscou 32': 264. 1859. 



"iClethra serrulata Turcz. Bull. Soc. Nat. Moscou 362: 233. 1863. 



Clethra palmeri Britton, N. Amer. Fl. 29: 8. 1914. 



Clethra schlechtendalii Briq. Ann. Cons. Jard. Geneve 20: 370. 1919. 



Durango to Veracruz, Morelos, Guerrero, and Michoac^n. 



Shrub or small tree, 9 meters high or less, the branchlets brownish-tomentose ; 

 leaves obovate to oval, 6 to 20 cm. long, 4 to 10 cm. wide, acute or obtuse, 

 serrate or entire, densely tomentose beneath ; racemes dense, 10 to 20 cm. long ; 

 pedicels 1.5 to 4 mm. long ; calyx 3.5 to 4.5 mm. long. " Jaboncillo " (Durango). 



The flowers, as in other species, are very fragrant. 



