A tree 40 to 60 ft, sometimes more, high; bark as in the white ash, but less deeply furrowed; young shoots clothed more or less densely with a pale down. Leaves up to 1 ft long; leaflets seven or nine (occasionally five), oblong-lanceolate or narrowly oval, 3 to 6 in. long, 1 to 2 in. wide, broadly tapered at the base, long and slenderly pointed, rather obscurely toothed, or entire, especially at the lower half, dull green on both surfaces, and nearly or quite glabrous above, except along the sunken midrib which sometimes is downy, covered beneath with a pale down. The leaflets, especially the lower ones, are stalked, the stalks grooved and downy, as is also the common stalk. Male and female flowers occur on separate trees, and are produced on the old wood just below the new shoot. Fruits 1 to 2 in. long, rather variable in shape; wing extending half-way or more down the cylindrical body.
American foresters and many botanists no longer make a distinction between the red ash (i.e., typical F. pennsylvanica) and the following variety:
var. subintegerrima (Vahl) Fern. F. lanceolata Borkh.; F. pennsylvanica var. lanceolata (Borkh.) Sarg. – Branchlets glabrous; leaves glabrous except for some down on the veins beneath. According to Sargent this tree, as seen in the east, is distinct enough from typical F. pennsylvanica, ‘but trees occur over the area which it inhabits, but more often westward, with slightly pubescent leaves and branchlets which may be referred as well to one tree as to the other’. This glabrous extreme of F. pennsylvanica was once distinguished as the ‘green ash’, but this name is now used by American foresters for the species as a whole.
F. pennsylvanica (including the above variety) has a wide range in N. America from the Atlantic to the Rockies and is usually found on wetter soils than the white ash (F. americana). As common in gardens as that species, it is not so effective and large a tree, although it grows quickly when young. A tree in the Oxford Botanic Garden, which was 50 × 3 ft when H. J. Elwes measured it early this century, is now 78 × 8 ft (1962). There is another at Hergest Croft, Heref., 65 × 51⁄2 (1961). At Kew the var. subintegerrima is represented by two trees, the larger, pl. 1897, 50 × 51⁄2 ft (1969).
F. pennsylvanica in its typical state is easily enough distinguished from F. americana by its downy shoots, but the glabrous forms are easily confounded with that species. See further under F. americana.
cv. ‘Aucubifolia’. – Leaflets mottled with yellow. This garden variety in some of its characters is intermediate between the typical state of F. pennsylvanica and the var. subintegerrima; the leaves are far from being as downy as in the former, but the shoots are quite downy. A handsome variegated tree.
F. berlandierana DC. – This ash was described by De Candolle from specimens collected by Berlandier in Texas, and also occurs in Mexico. It is closely allied to F. pennsylvanica var. subintegerrima, differing in its smaller stature, thicker bark and smaller leaves with usually only five leaflets. As seen at Kew it was a pleasing small tree of free growth, with glossy, deep green leaflets, but is not now in the collection.