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510 Twigs slender, glabrous, or with slight pubescence near the tip only ; stipule-scars absent. Leaf-scars small, crescentic, set somewhat obliquely on slightly prominent pulvini, surrounded by a narrow raised rim, marked with three bundle dots. Buds conical, pubescent, and acute ; scales five or six, imbricated, pubescent, ciliate, reddish or greenish; terminal bud larger than the lateral buds which arise at an angle of about 45°. Pith solid, but interrupted by transverse woody partitions, showing on longitudinal section a ladder-like appearance.

The inner scales of the bud are accrescent ; and the base of the shoot is marked by ring-like scars, indicating where these scales have fallen off in the preceding spring.

This species is extremely variable in leaf, both in wild specimens and cultivated trees. This is well shown in the Strathfieldsaye tree, the leaves of which vary from a long elliptical acuminate to a short broad obovate obtuse outline; some are quite glabrous, whilst others are pubescent on the midrib and principal veins beneath. Usually the leaves are very shining above and coriaceous; but in a tree growing at Kew in a wood, they are dull above and thin in texture. In some specimens there are numerous glands on the under surface of the leaf; whilst in others, as in a specimen growing in the Arnold Arboretum collected by Elwes, no glands are visible. The fruit is also variable, being either terete or flattened. The tree occurs in America in very diverse stations, both on wet soils and on dry mountain slopes ; and this may explain the remarkable extent of its variation.

Var. biflora, Sargent, Silva N. Amer. v. 76, t. 218 (1893).

Nyssa biflora, Walter, Fl. Carol. 253 (1788); Loudon, Arb. et Frut. iii. 1317 (1838); Sargent, Trees N. Amer. 709 (1905).

Leaves smaller than in the type, very narrow, glabrous and glandular beneath, quite entire in margin. Fruit with an oval, flattened stone, narrowed at both ends and prominently ribbed. This variety is a small tree, rarely more than 30 feet high, growing in ponds on the pine barrens near the coast from N. Carolina to Louisiana. It usually has a trunk with a swollen base, and appears to be a form of the species which has adapted itself to life in water.

The cultivated trees mentioned by Loudon as being Nyssa biflora were all probably Nyssa sylvatica of the typical form.

Nyssa sylvatica is found in North America from Southern Ontario, where it grows to a good size near Niagara, and in New England, where I saw it in the neighbourhood of Boston 60 or 70 feet high, westwards to Central Michigan and South-Eastern Missouri, and southwards to Florida and Texas. It attains its largest size, according to Sargent, in the southern Appalachian Mountains, growing as high as 100 feet with a maximum girth of about 15 feet.’ It is found generally in wet soil on

1 But Ridgway measured a black gum in Wabash Valley, 125 feet high by 13 feet in girth, and 64 feet to the first limb.