1. Juglans cinerea Linnaeus, Syst. Nat. ed. 10. 1272. 1759.
Butternut, white walnut, noyer cendré
Wallia cinerea (Linnaeus) Alefeld
Trees , to 20(-30) m. Bark light gray or gray-brown, shallowly divided into smooth or scaly plates. Twigs with distal edge of leaf scar straight or nearly so, bordered by well-defined, tan-gray, velvety ridge; pith dark brown. Terminal buds conic, flattened, 12-18 mm. Leaves 30-60 cm; petiole 3.5-12 cm. Leaflets (7-)11-17, ovate to lanceolate or oblong-lanceolate, ± symmetric, (2.5-)5-11(-17.5) × 1.5-6.5 cm, margins serrate, apex acuminate; surfaces abaxially with abundant 4-8-rayed fasciculate hairs, scales, and sometimes capitate-glandular hairs, axils of proximal veins with prominent tufts of fasciculate hairs, adaxially with scattered fasciculate hairs or becoming glabrescent; terminal leaflet present, usually large. Staminate catkins 6-14 cm; stamens 7-15 per flower; pollen sacs 0.8-1.2 mm. Fruits 3-5, ellipsoid to ovoid or cylindric, 4-8 cm, smooth, with dense capitate-glandular hairs; nuts ellipsoid to subcylindric or ovoid, 3-6 cm, surface with ca. 8 high, narrow, longitudinal main ridges, with narrow, interrupted, longitudinal ridges or lamellae between main ridges.
Flowering spring (Apr-Jun). Rich woods of river terraces and valleys, also dry rocky slopes; of conservation concern; 0-1000 m; N.B., Ont., Que.; Ala., Ark., Conn., Del., Ga., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis.
The butternut canker is killing Juglans cinerea across its range. Because the trees do not root-sprout, the range is contracting.