ELM FAMILY 207 



2. CELTIS (Tourn.) L. HACKBERRY. 



Shrubs or trees, with thin smooth or corky-ridged bark. Leaves oblique, 

 S3rrate or entire, 2-ranked, membranous or leathery. Flowers polygamo- 

 m&noecious or monoecious, axillary, the staminate solitary or clustered; the 

 pistillate usually solitary. Calyx 4- or 5-lobed, deciduous. Stamens 4 or 5; 

 filaments incurved; anthers extrorse. Ovary sessile, 1-celled, with 2 recurved 

 stigmas. Drupe globose or ellipsoid, with scant pulp and bony stone. 



Leaf-blades neither coriaceous nor pale beneath, nor strongly rugose. 



Leaves smooth above. 1. C. occidentalis. 



Leaves very rough, pustulate-scabrous above. 2. C. crassifolia. 



Leaf-blades coriaceous, strongly reticulate and rugose, paler beneath, often yellowish 



green. 

 Leaf-blades strongly pubescent beneath. 



Pedicels 15-20 mm. long, more than twice as long as the fruit; leaf-blades toothed. 



3. C. rugulosa. 

 Pedicels 4-10 mm. long, usually less than twice as long as the fruit; leaf-blades 



subentire. 4. C. reticulata. 



Leaf-blades glabrous beneath, or slightly hispidulous on the veins and in their axils. 



5. C. Douglasii. 



1. C. occidentalis L. A small tree, sometimes 20 m. high; bark of the 

 jsiem gray, corky-ridged; leaf-blades ovate to ovate-lanceolate, pubescent on 

 the veins beneath, thin, very oblique at the base, usually sharply serrate, short- 

 acuminate, 3-10 cm. long; pedicels in fruit 1-2 cm. long, nearly glabrous; fruit 

 globose, 7-10 mm. in diameter, purple or blackish. Rocky places: Que. N.C. 

 Okla . w Neb. Man. Plain. Ap-My. 



2. C. crassifolia Lam. A tree occasionally 40 m. high; bark corky-rough- 

 ened and warty; leaf -blades ovate or ovate-lanceolate, dark green, short-acumin- 

 ate, usually coarsely toothed, 3-10 cm. long, hirsute beneath, especially on the 

 veins; pedicels in fruit 1-2 cm. long; fruit globose or nearly so, 8-10 mm. in 

 diameter, black. Woods and hillsides: Mass. S.C. Colo. -S.D. Plain 

 Submont. Ap-Je. 



3. C. rugulosa Rydb. A tree 5-10 m. high, with round crown; twigs 

 somewhat pubescent when young; leaf -blades broadly ovate, oblique, 4-7 cm. 

 long, somewhat cordate at the base, short-acuminate, sharply serrate except at 

 the base and apex, dark green, shining and slightly scabrous above, brownish or 

 yellowish green and dull beneath ; fruit globose, about 8 mm. in diameter, brownish; 

 style short but evident. C. rugosa Rydb., not Newberry. Valleys in the foot- 

 hills: Colo. Submont. My. 



4. C. reticulata Torr. A shrub 1-5 m. high; bark gray, corky-ridged; 

 branchlets densely pubescent, brownish gray; leaf-blades broadly ovate, acute, 

 cordate at the base, 2-4 cm. long, entire or with a few broad teeth, shining above, 

 pale brown and densely hirsutulous beneath; fruit globose, 6-10 mm. in 

 diameter, red. Dry rocky places: Tex. Kans. Colo. -N.M. Son. Staked 

 Plains. Ap. 



5. C. Douglasii Planch. A low tree or shrub 5-10 m. high; twigs sparingly 

 pubescent; leaf-blades oblique, lance-ovate or ovate, gradually acuminate or 

 acute, more or less serrate, 2-6 cm. long, dark green above, light yellowish green 

 and reticulate beneath; pedicels 10-15 mm. long; fruit greenish brown to 

 nearly black, about 6 mm. in diameter, somewhat ellipsoid; style obsolete. 

 Hills: Ore. Utah Ida. B.C. Submont. Son. Ap-Je. 



FAMILY 35. CANNABINACEAE. HEMP FAMILY. 



Herbs or vines, with mostly opposite leaves and persistent stipules. Stam- 

 inate flowers in panicled racemes; sepals and stamens 5. Pistillate flowers 

 in bracted spikes, with a cup-like calyx; pistil of 2 united carpels, but ovary 

 1-celled. Fruit an achene; seed solitary, pendulous. 



Erect herbs; leaves digitately divided to near the base; pistillate flowers in axillary stiff 

 spikes. . 1. CANNABIS. 



Twining vines; leaves merely digitately lobed; pistillate flowers in drooping ament-hk e 

 spikes with imbricate bracts. 2. HUMULU S> 



