WALNUT FAMILY. 483 
Family 2. JUGLANDACEAE Lindl. Nat. Syst. Ed. 2, 180. 1836. 
WALNUT FAMILY. 
Trees with alternate pinnately compound leaves, and monoecious bracteolate 
flowers, the staminate in long drooping aments; the pistillate solitary or several 
together. Staminate flowers consisting of 3—numerous stamens with or without 
an irregularly lobed perianth adnate to the bractlet, very rarely with a rudi- 
mentary ovary. Anthers erect, 2-celled, the sacs longitudinally dehiscent; 
filaments short. Pistillate flowers bracted and usually 2-bracteolate, with a 
3-5-lobed (normally 4-lobed) calyx or with both calyx and petals, and an 
inferior 1-celled or incompletely 2—4-celled ovary. Ovule solitary, erect, orthot- 
ropous; styles 2, stigmatic on the inner surface. Fruit in our genera a drupe 
with indehiscent or dehiscent, fibrous or woody exocarp (husk; ripened calyx; 
also regarded as an involucre), enclosing the bony endocarp or nut which is 
incompletely 2—4-celled. Seed large, 2-4-lobed. Endosperm none. Cotyledons 
corrugated, very oily. Radicle minute, superior. 
Six genera and about 35 species, mostly of the warmer parts of the north temperate zone. 
extending in America south along the Andes to Bolivia. The young leaves in the bud are stipulate 
in at least two species of //icoria, 
Husk indehiscent; nut rugose. 1. Juglans. 
Husk at length splitting into segments; nut smooth or angled. 2. Hicoria. 
5 JUGLANS Wasp bleoo7en) 1753. 
Trees, with spreading branches, superposed buds, fragrant bark, and odd-pinnate leaves, 
with nearly or quite sessile leaflets, the terminal one sometimes early perishing. Staminate 
flowers in drooping cylindric aments, borne on the twigs of the previous year; perianth 3-6- 
lobed; stamens 8-40 in 2 or more series. Pistillate flowers solitary or several together on a 
terminal peduncle at the end of shoots of the season, the calyx 4-lobed, with 4 small petals 
adnate to the ovary at the sinuses; styles fimbriate, very short. Drupe large, globose or 
ovoid, the exocarp somewhat fleshy, fibrous, indehiscent, the endocarp bony, rugose or 
sculptured, 2-4-celled at the base, indehiscent, or in decay separating into 2 valves. [Name 
a contraction of the Latin /ovis glans, the nut of Jupiter. ] 
About 8 species, natives of the north temperate zone, one in the West Indies, 1 or 2 in the 
Andes of South America. Besides the following 1 or 2 others occur in the southwestern United 
States. 
Fruit globose, obtuse, not viscid; petioles puberulent. 1. J. nigra. 
Fruit oblong, pointed, viscid; petioles pubescent. 2. J. cinerea. 
1. Juglans nigra L. Black Walnut. 
(Fig. 1149.) 
Juglans nigra l,. Sp: Pl. 997. 1753. 
A large forest tree with rough brown bark, 
maximum height about 150°, trunk diameter 8°, 
the twigs of the season and petioles puberulent, 
the older twigs glabrous or very nearly so. 
Leaflets 13-23, ovate-lanceolate, more or less 
inequilateral, acuminate at the apex, rounded or 
subcordate at the base, serrate with low teeth, 
glabrous or very nearly so above, pubescent be- 
neath, 3/-5’ long, 1/-2’ wide; staminate aments 
solitary in the axils of leaf-scars of the preced- 
ing season, 3/-5’ long; drupes usually solitary 
or 2 together, globose or a little longer than 
thick, 1%4/’-3/ in diameter, glabrous but papil- 
lose, not viscid; nut corrugated, slightly com- 
pressed, 4 celled at the base. 
In rich woods, Massachusetts to southern Onta- 
rio and Minnesota, south to Florida, Kansas and 
Texas. Wood strong, hard, rich brown; weight per 
cubic foot 38 lbs. April-May. Fruit ripe Oct.-Nov. 
