228 MISC. PUBLICATION -12 3, U. S. DEPT. OF AGRICULTURE 



26. ULMACEAE. Elm family 



1. CELTIS. Hackberry 



Trees or shrubs; leaf blades unequal at base, very rough above; 

 flowers perfect or unisexual, axillary, solitary or in small clusters; 

 perianth 5- or 6-parted; style none, the stigmas elongate, spreading or 

 recurved, plumose; ovary 1-celled; fruit a globular drupe with thin 

 flesh and a hard-shelled stone, mostly yellow to dull red at maturity. 



Hackberries are browsed by cattle when other forage is scarce, 

 and the sweet but rather dry and insipid fruits are relished by birds 

 and small desert mammals. The Papago and probably other Indians 

 gather the fruits for food. The wood is sometimes used for fence 

 posts. 



Key to the species 



1. Plant a spiny, intricately branched shrub; leaf blades not more than 2 cm- 

 wide, elliptic to oblong-ovate, rounded to acutish at apex, entire or spar- 

 ingly crenate-dentate, not reticulate- veined; herbage puberulent. 



1. C. PALLIDA. 



1. Plants large shrubs or small trees, not spiny or intricately branched; leaf 

 blades more than 2 cm. wide, ovate or lance-ovate, acute to sharply acumi- 

 nate at apex, obliquely cuneate to obliquely cordate at base, serrate- 

 dentate or entire, more or less prominently reticulate- veined beneath; 

 twigs, petioles, and lower surface of the leaf blades (especially the veins) 

 short-pilose (usually sparsely so) to nearly glabrous; bark warty. 



2. C. RETICULATA. 



1. Celtis pallida Torr., U. S. and Mex. Bound. Bot. 203. 1859. 

 Greenlee, Pinal, Maricopa, Cochise, and Pima Counties, 1,500 to 



3,500 feet, foothills and mesas, often forming dense thickets. Western 

 Texas to Arizona and northern Mexico. 



Granjeno. This is reportedly of value as a honey plant and for 

 erosion control. 



2. Celtis reticulata Torr., Ann. Lye. N. Y. 2: 247. 1828. 



Celtis occidentalis L. var. reticulata Sarg., Cat. Forest Trees 

 Amer. 126. 1884. 



Almost throughout the State, 2,500 to 6,000 feet, usually along 

 streams. Oklahoma and Colorado to Arizona and northern Mexico. 



Netleaf hackberry, paloblanco. The species is highly variable in 

 the shape, thickness, and pubescence of the leaves and prominence of 

 the veins, also in length of the pedicels, but there is so much inter- 

 gradation that recognition, even of varieties, is difficult. C. brevipes 

 Wats, is a form with pedicels somewhat shorter than to about equaling 

 the petioles. At the other extreme are specimens from the Grand 

 Canyon, referred by Sargent to C. douglasii Planch., with serrate, 

 long-acuminate, more or less cordate leaf blades and pedicels up to 

 2 cm. long and 2 to 4 times as long as the petioles. C. douglasii is 

 described as having brownish purple fruits, whereas in C. reticulata 

 they are normally orange-colored at maturity. 



27. MORACEAE. Mulberry family 



Small trees, shrubs, or nearly herbaceous plants with twining stems; 

 flowers mostly dioecious, without petals, those of both sexes, or the 

 pistillate ones only, in catkins. 



