50 FOUNDATIONS OF BOTANY 
flowers solitary or in small clusters. Calyx 3—5-lobed, minute 
petals sometimes present. Ovary 1-celled or incompletely 
2-4-celled. Fruit with a dry husk enclosing a bony nut.* 
I. JUGLANS, L. 
Staminate catkins cylindrical, solitary, borne on wood of 
the previous year, stamens numerous, filaments short, calyx 
4-6-parted. Pistillate flowers single or a few together ona 
short peduncle at the base of the growth of the season. Calyx 
4-parted. Petals 4, minute, adnate to the ovary. Styles 2, 
short, plumose. Fruit large, roundish or oval, husk fibrous- 
fleshy, becoming dry, indehiscent, nut bony, very rough.* 
1. J. nigra, L. Brack Watnut. Leaflets 13-21, ovate-lanceo- 
late, serrate, taper-pointed, somewhat cordate or oblique at the base, 
nearly smooth above, downy beneath, petioles minutely downy. 
Fruit usually single, roundish, about 2 in. in diameter. On rich 
soil, rare near the coast. One of the most valuable of our native 
trees, the wood being very durable and highly prized for cabinet 
work.* 
2. J. cinerea, LL. Buttrernut. Leaflets 15-19, ovate-lanceolate, 
taper-pointed at the apex, rounded or slightly unsymmetrical at the 
base, serrate, downy beneath; petioles, branchlets, and fruit clothed 
with short, sticky hairs. Fruit often somewhat in clusters, oblong, 
large. More common northward. Wood less valuable and nut less 
oily than the black walnut. The English walnut (J. regia) is 
occasionally seen in cultivation. It has 7-11 leaflets and a nearly 
smooth nut.* 
Il. CARYA, Nutt. 
Leaflets serrate; staminate catkins usually in threes on a 
common peduncle, or sometimes sessile at the base of the 
growth of the season; calyx 2-3-parted, stamens 3-10, fila- 
ments short. Pistillate flowers 2-5 in terminal clusters, 
calyx 4-parted, petals none, styles 2 or 4, fringed. Fruit 
somewhat globular, husk separating more or less completely 
into 4 valves. Nut smooth or angled.* 
1. C. oliveformis, Nutt. Pecan. A large tree with rough gray 
bark, young twigs and leaves downy, nearly smooth when mature. 
Leaflets 11-15, oblong-lanceolate, acuminate, serrate, scythe-shaped. 
Staminate catkins nearly sessile, 5-6 in. long. Husk thin nut oval 
