JUGLANDACEAE 333 
Leaflets with lanceolate or narrowly-lanceolate blades: fruits 5-8 em. in diameter. 2. J. nigra. 
Leaflets with ovate or ovate-lanceolate blades: fruits about 2 em. in diameter. 3. J. rupestris. 
1. Juglans cinérea L. A tree, reaching a maximum height of about 30 m., with a 
trunk diameter of 1 m., the heart-wood pale, the bark light brown. Leaves 3-6 dm. long, with 
stout pubescent petioles ; leaflets 11-17, the blades lanceolate or oblong-lanceolate or oblong, 
6-12 em. long, acute or acuminate at the apex, serrate, inequilateral at the base, sessile or 
short-stalked, viscid-pubescent, but at length glabrous above: staminate aments 6-15 cm. 
long: anther with an apiculate appendage: fruits spicate, oblong, 8-12 em. long, usually 
acute, very viscid-pubescent : nut shaped like the husk, 1-celled above, 2-celled below the 
middle, the surface sculptured into thin brittle irregular longitudinal ridges. 
In moist soil or rich woods, New Brunswick to North Dakota, Georgia, Alabama, Arkansas and 
Nebraska. BUTTERNUT. WHITE WALNUT. 
2. Juglans nigra L. A forest tree, reaching a maximum height of 50 m. and a trunk 
diameter of 2.5 m., producing a dark brown heart-wood, the bark dark brown, broken into 
broad ridges. Leaves 3-6 dm. long, with stout pubescent petioles ; leaflets 15-23 (the ter- 
minal one often suppressed), the blades 8-10 cm. long, ovate or ovate-lanceolate, acute or 
acuminate, serrate, rounded or subcordate at the inequilateral base, sessile or nearly so, 
becoming glabrous above, pubescent beneath: staminate aments 5-10 cm. long: anther 
tipped by the dilated connective : fruits globose or globose-ovoid, 5-8 cm. long, rounded at 
the apex, glabrous: nut globose-ovoid, slightly flattened, sometimes broader than high, 
2-celled above, 4-celled below the middle, the surface sculptured into thick irregular 
ridges. 
In rich soil, Massachusetts to Ontario and Minnesota, Florida, Texas and Nebraska. WALNUT. 
BLACK WALNUT. 
3. Juglans rupéstris Engelm. A small tree, sometimes reaching a height of 16 m. 
and a trunk diameter of 1.5 m., the bark pale, deeply furrowed. Leaves 2-3 dm. long, with 
slender pubescent petioles ; leaflets 9-23, the blades lanceolate or narrowly-lanceolate, 
acuminate, distantly serrate with appressed rather blunt teeth, often scythe-shaped, inequi- 
lateral, especially near the base, short-stalked, pubescent when young, usually becoming 
glabrous in age: staminate aments 5-10 cm. long: anther tipped by the dilated connec- 
tive: fruits globose, about 2 em. in diameter, solitary, or often 2 together, glabrous: 
nut subglobose, grooved, 4-celled below the middle. : 
In valleys, middle Texas to New Mexico and northern Mexico. WALNUT. 
2. HICORIA Raf. 
Trees, cylindric in outline, with hard and very tough wood, a watery sap, and a close 
or scaly bark. Pith solid. Leaflets involute in vernation: blades usually leathery. 
Staminate aments often branched, clustered on the twigs of the preceding year or at the 
base of the twigs of the present year, mostly long-stalked : calyx 3-lobed or rarely 2-lobed, 
subtended by an almost free bract ; this longer than‘the calyx-lobes: stamens 3-10, in 
several rows : anthers 2-celled, pubescent, each notched at the apex ; sacs opening length- 
wise, with an inconspicuous connective. Pistillate flowers in spike-like clusters at the ends 
of the twigs of the present year: calyx of 1 sepal adnate on the ovary : ovary inferior : 
stigmas spreading. Fruit subglobose, obovoid or cylindric: husk becoming dry, 4-valved, 
splitting more or less readily to the middle or base, its angles sometimes winged : nut 
smooth, thin-walled or thick-walled, more or less flattened. Seed sweet or bitter. [Carya 
Nutt.] The plants flower in the spring and mature their fruit in the fall. 
kn Poe tue entire or merely notched at the apex : nuts terete or slightly flattened, smooth and even, 
flets 5-9: nuts with exceedingly thick shells. 1. H. myristicaeformis. 
Leaflets 9-15: nuts with thin shells. 
Leaflets with stalked blades: nut terete: seed sweet. 2. H. Pecan. 
i Leaflets with sessile or nearly sessile blades: nuts flattened: seed bitter. 3. H. Texana. 
Cotyledons deeply 2-lobed : nuts markedly flattened, usually uneven. 
Bud-scales valvate : lateral leaflets mostly falcate. 
Leaflets 9-13, glabrous: nuts corrugated. 4. H. aquatica. 
Leaflets 5-9, pubescent beneath : nuts smooth. s 5. H. minima. 
Bud-scales imbricated : lateral leaflets not falcate. 
* Middle lobe of the staminate calyx, much larger than the lateral : husk 
of the fruit freely splitting to the base. 
Bark close, but rough : foliàge scurfy or pubescent. 
Rachis of the leaves and staminate aments scurfy pubescent at least 
when young. 
Rachis of the leaves and staminate aments densely hirsute. 
Bark shaggy, separating in long plates : foliage glabrous or puberulent. 
fLeaflets 7-9: nuts pointed at both ends. 8. H. laciniosa. 
No 
. H. pallida. 
H. alba. 
