ULMACEAE. 337 



beneath, 6-13 cm. long, 5-8 cm. wide, mostly acute or short-acuminate at the apex, 

 narrowed at the base, the teeth short, triangular ; petioles slender, 6-18 mm. long; 

 iruit sessile ; cup hemispheric, thin, about 1.2 cm. broad and one-half as high, its 

 bracts floccose, triangular-ovate or oblong lanceolate, appressed ; acorn ovoid, 

 obtuse, 2-3 times as long as the cup; seed sweet. In dry sandy or rocky soil, Me. 

 to Minn., Ala. and Tex. April-May. Acorns ripe Sept.-Oct. 



26. Quercus Virginiana Mill. Live Oak. (I. F. f. 1249.) A tree, with 

 rough brown bark; often shrubby, the young shoots puberulent. Leaves evergreen, 

 coriaceous, oblong, elliptic or oblanceolate, obtuse, entire or with a few bristle- 

 tipped teeth, bright green and glabrous above, pale green and puberulent or becom- 

 ing glabrous beneath, 2-8 cm. long; petioles stout, 2-6 mm. long; fruit peduncled; 

 cup nearly hemispheric, 1-1.6 cm. broad, its bracts closely appressed, ovate or 

 lanceolate ; acorn ovoid-oblong, about twice as high as the cup ; seed not edible. 

 In dry soil. Va. to Fla., Tex. and Mex., mostly near the coast. Also in Cuba. 

 March-April. Acorns ripe Sept.-Oct. [Q. virens Ait.] 



Order 9. URTICALES. 



Trees, shrubs or herbs, the flowers with a calyx but without corolla, 

 small, not borne in aments, monoecious, dioecious or polygamous ; ovary 

 1 -celled, superior. 



Fruit not an achene (except in Humulus and Cannabis of the Moraceae) : trees, shrubs 

 or herbs ; ovule pendulous. 



Trees with alternate leaves, the sap not milky. Fam. i. Uhnaceae. 



Trees with alternate leaves and milky sap ; or opposite-leaved herbs or herbaceous 

 vines. Fam. 2. Moraceae. 



Fruit an achene; herbs with small clustered greenish flowers; ovule erect or ascending. 



Fam. 3. Urticaceae. 



Family I. ULMACEAE Mirbel. 

 Elm Family. 

 Trees or shrubs, with alternate simple serrate petioled pinnately veined 

 stipulate leaves, the stipules usually fugacious. Flowers small, monoe- 

 cious, dioecious, perfect or polygamous, clustered, or the pistillate solitary. 

 Perianth 3-9-parted or of 3-9 distinct sepals. Petals none. Stamens in 

 our species as many as the perianth-lobes or sepals and opposite them ; 

 filaments straight ; anthers ovate or oval, longitudinally dehiscent. Ovary 

 1 -celled (rarely 2-celled), mostly superior ; ovule solitary, pendulous, anat- 

 ropous or amphitropous ; styles or stigmas 2. Fruit a samara, drupe or 

 nut. Endosperm of the seed little or none. Embryo straight or curved ; 

 cotyledons mostly flat. About 13 genera and 140 species, widely distrib- 

 uted in temperate and tropical regions. 



Flowers borne in clusters on twigs of the preceding season ; fruit a samara or nut-like. 

 Flowers expanding before the leaves; calyx 4-9-cleft; fruit a samara. 1. Ulmui 

 Flowers expanding with the leaves; calyx 4-5-cleft ; fruit nut-like. 2. Planerct* 



Flowers borne on twigs of the season, the pistillate mostly solitary; fruit a drupe. 



3. Celtis. 



1. ULMUS L. 



Trees, with 2-ranked straight-veined inequilateral leaves. Flowers perfect or 

 polygamous. fascicled or racemose, usually unfolding before the leaves, borne 

 axillary on the twigs of the preceding season. Calyx campanulate, 4-9 lobed. per- 

 sistent, its lobes imbricated. Fiiaments erect, slender, exserted. Ovary sessile or 

 stalked, compressed. Styles 2, divergent, stigmatic along the inner margin. Fruit a 

 i-seeded flat orbicular or oval samara, its membranous wings continuous all around 

 except at the apex, commonly as broad as or broader than the body. Embryo 

 straight. [The ancient Latin name ot the elm; Celtic elm.] About 18 species, 



