3. Fraxinus pennsylvanica Marshall (green ash, red ash)
F. pennsylvanica var. subintegerrima (Vahl)
Fernald
Pl. 461 a, b;
Map 2097
Plants trees to
25 m tall with a somewhat spreading, oval crown, dioecious or incompletely
dioecious. Twigs circular in cross-section, unwinged, glabrous or minutely
hairy, not glaucous, gray to grayish green or brown with relatively
conspicuous, pale, circular to elongate lenticels, the leaf scars truncate to
shallowly concave on the apical side on both new and older twigs. Terminal buds
3–8 mm long, ovoid to conic, longer than wide, bluntly to sharply pointed at
the tip, brown to rust-colored, glabrous or scurfy-hairy, with usually 3 pairs
of scales, the outermost pair relatively short and tightly to loosely
appressed. Leaves 5–30 cm long, the petiole glabrous or hairy. Leaflets mostly
(5)7(9), 1.5–16.0 cm long, 0.5–7.5 cm wide, variable in shape but mostly
lanceolate to narrowly ovate, narrowly elliptic, or elliptic (the basalmost
pair sometimes broader), mostly angled or tapered to the often narrowly winged
stalk (this mostly 5–12 mm long on the terminal leaflet and 2–6 mm long on
lateral leaflets), relatively thin to slightly leathery, the upper surface
glabrous or sparsely short-hairy, dull to slightly shiny, the undersurface
glabrous or sparsely to densely short-hairy, sometimes only along the veins,
yellowish green to pale green but not whitened, the margins entire or more
commonly with blunt teeth. Calyces present, persistent at fruiting, 0.5–1.5 mm
long. Fruits 30–60 mm long, the slender stalk 5–10 mm long, the body 10–25 mm
long, 1.5–3.5 mm wide, slender, narrowly oblong in outline, not flattened, the
wing 3–6 mm wide, narrowly oblanceolate to narrowly oblong-lanceolate, more or
less rounded at the tip, less commonly with a small notch, extending mostly
1/3–1/2 the way along each side of the body. 2n=46. April–May.
Common
throughout the state (eastern U.S. west to Montana and New Mexico; Canada,
Mexico). Bottomland forests, swamps, banks of streams, rivers, and spring
branches, margins of ponds, lakes, and sinkhole ponds, bases of bluffs,
bottomland prairies, loess hill prairies, edges of marshes and fens; also
ditches, fallow fields, pastures, railroads, roadsides, and moist disturbed
areas.
Green ash leaves
and twigs are variable in pubescence. In Missouri, most plants have glabrous
leaves and twigs and have been segregated by some authors as var. subintegerrima
(Steyermark, 1963). Pubescent individuals are less commonly encountered, but
still widely distributed in the state, and are not considered worthy of formal
taxonomic recognition (G. N. Miller, 1955; Hardin, 1974). In contrast, the two
other subspecies of F. pennsylvanica accepted by G. N. Miller (1955)
from the western United States, now generally are regarded as separate species.
Vegetative
specimens of green ash can be difficult to identify. The cuticular structures
of the lower leaflet surfaces of white ash (see discussion under that taxon)
are lacking in green ash, a character that can be helpful in laboratory
determinations.
Green ash wood
is slightly inferior to white ash but is used for many of the same purposes and
is faster growing. The species is grown commonly along streets and in other
horticultural plantings, even at upland sites, because of its tolerance of a
wide range of environmental conditions. The fruits mature as early as June and
are wind-dispersed in autumn, with many persisting on the tree into winter.
Seedlings can be weedy and are a nuisance to gardeners with pistillate trees in
their neighborhoods. The species also is sometimes cultivated in Central
America, South America, and the Old World.