| Inner bark mucilaginous; leaves very rough above; flowers nearly sessile; fruit not ciliate | [1 U. fulva.] |
| Inner bark not mucilaginous; leaves smooth or somewhat rough above; flowers on slender pedicils; fruit ciliate. | |
| Branches without corky wings; sides of samara glabrous | [2 U. americana.] |
| Branches (at least some of them) with corky wings; at least one side of the samara pubescent. | |
| Buds ovate, not twice as long as wide, obtuse, or short-pointed, dark brown; scales pubescent and ciliate; leaves usually not twice as long as wide, base of petiole glabrous beneath; calyx lobes 7-9 | [3 U. Thomasi.] |
| Buds small, narrow, twice as long as wide, very sharp-pointed, light brown; scales glabrous or merely puberulent; leaves usually twice as long as wide, base of petiole pubescent all around | [4 U. alata.] |
1. Ulmus fúlva Michaux. Slippery Elm. Red Elm. [Plate 57.] Fairly large trees with deeply fissured reddish-brown bark without white streaks between the layers of the ridges, twigs very pubescent and green at first, becoming gray or reddish-brown at the end of the season and remaining more or less pubescent for a year or more; buds ovate, a very dark reddish brown, the scales more or less pubescent; leaves ovate, oval or slightly obovate, average blades 8-15 cm. long, hairy on both surfaces at first, remaining more or less pubescent beneath until maturity, and becoming very rough above with a few scattered hairs remaining, fragrant when dried, fragrance remaining for years; fruit ripening the last of April or the first of May before or with the unfolding of the leaves; samara orbicular or obovate, usually longer than wide, average size 13-17 mm. long and 9-12 mm. wide, the margin as wide or wider than the seed, margin glabrous, seed densely pubescent on both sides; wood hard, strong, light when well seasoned and not warping as badly as white elm.
Distribution.—Quebec south to Florida, west to Texas, Nebraska and North Dakota. Found in all parts of Indiana. In the prairies or in the "flats" it may be absent in one or more contiguous counties and may be entirely absent on the crests and upper slopes of ridges. It prefers a moist well drained soil, and where it is found it is usually a frequent to a common tree, although rarely is it found as a very common tree. It is usually associated with sugar maple, beech, white ash, linn, tulip, white oak, etc.
Remarks.—This tree usually is from 3-6 dm. in diameter and tall for its diameter. However, larger trees occur. In the Ind. Geol. Rept. 6:70:1875 mention is made of a tree in Jackson County that was "18 feet in circumference." The uses of the wood are similar to that of white elm. The inner bark collected in spring is much used in medicine under the name of slippery elm.
ULMUS FULVA Michaux. Red or Slippery Elm. (× 1/2.)