FRAXINUS QUADRANGULATA Michaux. Blue Ash. (× 1/2.)
This species has not been observed in the "knob" area of the State or anywhere in the flats of the Lower Wabash Valley. Schneck reports it as rare on the hills of this area. The tree is too rare to definitely determine its associates, although sugar maple is usually found with it.
Remarks.—This species is becoming too scarce to be of much economic importance. The cut is usually sold as white ash. The uses of the wood are practically the same as the white ash.
The fruit and foliage of this species most closely resembles that of the black ash, from which it can be distinguished by its greenish-yellow foliage and the habitat in which it grows.
7. Fraxinus nìgra Marshall. Black Ash. [Plate 130.] Medium sized, tall and straight trees with a light gray bark, broken up into small thin plates on old trunks; twigs round, robust and smooth at maturity; leaves 2.5-4 dm. long, leaflets generally 7-11 and 7-13 cm. long, sessile, the terminal one generally on a stalk 0.5-1 cm. long, oblong or oblong-lanceolate, narrowed or rounded at the base, and short or long acuminate at the apex, margins coarsely and rather irregularly serrate with short teeth which are usually somewhat incurved, dark green and glabrous above, not much lighter beneath and glabrous or pubescent along the midrib and larger veins; calyx and corolla none; fruit ripens the last of June to August, similar to the fruit of the blue ash, samaras generally 3-4 cm. long, and 7-10 mm. wide, body winged all around, the base of the samara rounded, the apex notched or rounded, the apical end of the samara twisted more or less to the right in all specimens at hand.
Distribution.—Nova Scotia to Manitoba, south to Virginia and northern Arkansas. Local in all parts of Indiana except in the "knob" area of the State. It is generally found in places that are inundated much of the winter season. Its habitat is in cold swampy woods or similar places about lakes. It has no special affinity for streams. It is local in its distribution. Where it is found it is generally a frequent to common tree. In the lake area of Indiana its habitat conditions are frequent, consequently colonies of it are frequent. South of the lake area of the State it becomes rare to extremely local. In the southwest part of the State it has been sparingly found in a few cypress swamps. It is usually associated with white elm, cottonwood, aspens, red maple, bur oak, and is one of the first species to invade extinct tamarack swamps.