America, four species extending as far north as Canada, and one species confined to the high lands of Mexico. Six species! (Plate 203) are in cultivation in the British Isles, and will be dealt with in the following account.
The genus is divided into two sections :—
1. Apocarya, De Candolle, Prod. xvi, 3, p. 144.
- Buds, with four to six valvate scales, which are often obscurely pinnatifid at
the apex; axillary buds, often two to three superposed, the uppermost one stalked. Husk of the fruit thin, and prominently ridged at the sutures.
1. Carya olivæformis, Nuttall.
- Buds greyish, densely pubescent, without glands. Leaflets, eleven to thirteen, rarely nine; margin densely ciliate.
2. Carya amara, Nuttall.
- Buds yellowish, slightly pubescent, glandular. Leaflets, seven to nine; margin irregularly ciliate.
II. Eucarya, De Candolle, Prod. xvi. 2, Pp. 142.
- Buds with ten to twelve imbricated scales, the outer falling early, the inner accrescent and becoming much enlarged and reflexed at maturity. Husk of the fruit thick, not ridged at the sutures.
* Leaflets five, pubescent.
3. Carya alba, Nuttall.
- Young branchlets with brown stellate hairs; base of the shoot marked with a dense pubescent ring. Leaflets, stellate-pubescent beneath, ciliate in margin.
** Leaflets five or seven, glabrous.
4. Carya porcina, Nuttall.
- Young branchlets glabrous or with only an occasional hair; base of shoot without pubescent ring. Leaflets glabrous beneath, except for axil-tufts, non-ciliate in margin.
*** Leaflets, seven or nine, pubescent.
5. Carya sulcata, Nuttall.
- Branchlets reddish-brown, glabrous towards the tip. Leaves not fragrant; rachis nearly glabrous ; nerves in upper lateral pair of leaflets more than twenty pairs.
6. Carya tomentosa, Nuttall.
- Branchlets purplish-grey, pubescent and glandular. Leaves fragrant; rachis pubescent and glandular; nerves in upper lateral pair of leaflets less than twenty pairs.(A.H.)
1 Carya aquatica, Nuttall, the water hickory, a native of river swamps in the southern parts of the United States, is not likely to succeed in any Part of the British Isles. Loudon, op. cit. 1444, mentions a tree of this species 40 feet high growing at Milford near Godalming ; but his identification was probably incorrect.
