Trees or shrubs with simple, alternate, 2-ranked, petioled leaves; sepals 3-9, petals none, stamens as many as the sepals and opposite them, stigmas 2.

1. ÚLMUS. The Elms.

Trees with furrowed bark; leaves short petioled, with lateral veins prominent and parallel, oblique or unequally heart-shaped at the base, taper-pointed at the apex, mostly double-serrate; flowers of Indiana species expanding before the leaves in March or April; fruit a samara surrounded with a wide membranous margin, maturing in the spring.

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.

Plate 57

2. Ulmus americÀna LinnÆus. White Elm. Plate 58. Large trees; bark deeply fissured, gray, the ridges showing white streaks between the layers; twigs more or less hairy at first and usually becoming glabrous by the end of the season; buds ovate, acute and glabrous; leaves ovate, oval or obovate, average blades 8-12 cm. long, hairy on both sides on expanding, becoming at maturity glabrous above and smooth or rough, sometimes very rough on vigorous young shoots, remaining pubescent beneath, rarely glabrous; fruit ripening before or as the leaves unfold, generally oval in shape, about 1 cm. long, both surfaces glabrous, margins about as wide as the seed and fringed with hairs; wood hard, tough, flexible, generally hard to split, warps badly in seasoning.

Distribution.—Quebec to Florida, west to Texas and Nebraska. Found throughout Indiana, and doubtless in every county. It is frequent to common or very common on the flood plains of streams, in wet woods and in low ground generally.

Remarks.—This species is also called water elm, swamp elm, gray elm, bitter elm, sour elm and in southwestern counties it is often called red elm. In Perry County it is often called hub elm. It is generally known as "elm" and when this term is used, it refers to this species. The wood has a very wide range of uses. The greatest amount has been used for hoops, staves and heading. Large quantities have been used in the manufacture of agricultural implements, hubs, furniture, basket handles, etc. White elm is usually considered very difficult to split, but I was informed by a pioneer timber cutter that the heart wood of the veterans of the forest splits as well as oak, and that he worked many a tree up into staves. He told me that he made into staves a tree in Paulding County, Ohio, that was eight feet in diameter at the stump. There is little attempt being made by woodlot owners to propagate this tree. However, the natural propagation of the species is probably greater than any other species because it produces seed at an early age, and culls of the forest are not cut because they are not good for fuel which leaves them to produce seed. Then the seed are light, and are scattered to great distances by the wind and water. It is propagated very easily from seedlings.

The tree when grown in the open has a tendency to be bushy and unless it is given some pruning will have a very short clear trunk. It has always been regarded as one of the best species for shade tree planting. For beauty of form it is not excelled by any tree for shade or ornamental planting. However, it has several insect enemies that require spraying to keep them under control.

Plate 58

3. Ulmus ThomÁsi Sargent. Hickory Elm. Rock Elm. Plate 59. Large trees; bark deeply fissured and grayish like the bark of the white elm; twigs light brown, generally densely hairy and remaining more or less pubescent until the end of the season or later, the twigs of some specimens are glabrous or only slightly hairy at first and soon become glabrous and somewhat glaucous, after the first year some of the branchlets begin to develop 1-4 corky ridges from a few millimeters to 5 or 6 mm. in thickness, the ridges are wide and rounded at the top, dark gray, brown and discontinuous, rarely a corky ridge will appear on a branchlet the first year; leaves oval or obovate, average blades 8-15 cm. long, at maturity glabrous and smooth or rough to very rough above, permanently pubescent beneath especially on the veins; fruit ripens late in May or early in June when the leaves are from ¹/₂ to ²/₃ grown; samara oval, usually 1.5-2 cm. long, oblique at the base, with a beak 2-5 mm. long at the apex, both faces pubescent, wing about as wide as the seed; wood hard heavy, strong, flexible, uses the same as white elm.

Distribution.—Southern Quebec and Ontario south to northern New Jersey and west to Minnesota and Missouri. The distribution in Indiana has not been studied. The frequency of its occurrence is not known, and all of the known stations are given. The published records are as follows: Dearborn (Collins); Franklin (Meyncke); Hamilton (Wilson); Jefferson (Barnes) and (Deam); Noble (VanGorder); Parke (Hobbs); St. Joseph (Nieuwland); Steuben (Bradner); Wayne (Petry and Markle); Wells (Deam). Additional records are Hendricks, Noble, Ripley, Vermillion and Wayne by Deam. The published record for Posey County by Deam and Schneck should be referred to Ulmus alata. It prefers a well drained soil and is most frequently found near the base of the slope or on the top of flood plain banks of streams, in ravines, or in a habitat like a beech-sugar maple woods. It is reported to have been frequent in Franklin, Noble and Wells Counties.

Its appearance and habit of growth is so much like the white elm that it is not commonly distinguished from it, which accounts for the lack of definite knowledge of its range in our area.

Plate 59

Plate 60

4. Ulmus alÀta Michaux. Winged Elm. Plate 60. Small to medium sized trees; bark rather closely fissured, grayish or reddish-brown, in appearance like white elm; twigs hairy at first, generally remaining more or less pubescent throughout the season, rarely becoming entirely glabrous before the end of the season, a light brown gradually becoming a gray-brown; branchlets usually begin to develop two thin narrow corky ridges, becoming by the end of the second year 4-7 mm. thick, the year's growth of corky layer a light brown, the older layers a darker brown, the two main corky ridges are on opposite sides of the twigs, and between these there are generally additional corky excrescences, especially on the older branches; leaves oblong-lanceolate or oval, some somewhat falcate, average blades 4-8 cm. long, pubescent on both sides on unfolding, becoming at maturity glabrous or nearly so above, some are rough above at maturity, remaining pubescent until maturity beneath; petioles short, generally 2-3 mm. long, rarely 5 mm. or longer; fruit ripening before or with the unfolding of the leaves; samara 6-10 mm. long, pubescent on both faces.

Distribution.—Virginia west through southern Indiana to southern Missouri, south to the Gulf and west to Texas. In Indiana it is confined to the southwestern part of the State. Gorby's report for Miami should be ignored. It has been reported as far north as Vigo and Monroe Counties by Blatchley, and as far east as Clark County by Baird and Taylor. The author has collected it in Crawford, Dubois, Martin, Orange, Perry, Posey, Spencer and Warrick Counties.

The tree has two rather distinct habitats. In the hill counties it is found on the sides of cliffs, steep slopes or on the top of the ridges with such species as the black, chestnut and scarlet oaks and chestnut. In this habitat it is usually a small scrubby tree with an excessive number of side branches. Such specimens usually have the corky ridges well developed on all of the branches and the tree presents a weird appearance. The second habitat is in the hard clay flats of the southwestern counties. In Warrick County along Big Pigeon Creek west of Boonville I measured a specimen 21 dm. in circumference and I estimated the clear bole at 8 m. It was associated with sweet gum, black gum, white elm, red birch, red oak, etc. It is found throughout this county both in the "flats" and on the sandy ridges. In Posey County it is a frequent tree in the low woods about 10 miles southwest of Mt. Vernon. In these woods it acquires a diameter of 3-6 dm. and is associated with post oak, Spanish oak, sweet gum, shingle oak, etc. It is to be noted that specimens that grow in these conditions and those that acquire a large size do not develop such conspicuous corky branches. A large tree over 6 dm. in diameter was noted in the eastern part of Gibson County growing in low sandy soil which was destitute of corky branches so far as could be seen from the ground. All of the branches examined were free from corky ridges, and only a few corky excrescences were present. The specimen could easily be identified by the leaves. Another large tree 12 dm. in circumference in a black oak woods 4 miles south of Marengo in Crawford County was also free from corky ridges.

This is an interesting tree and requires further study to establish its range in Indiana and to learn its habits. In Jasper, Indiana, it is a frequent shade tree. No doubt the trees were obtained from a nearby woods along the Patoka River where this species is known to occur.

2. CÉLTIS. The Hackberries.

Trees with pith of branchlets chambered; flowers in Indiana species appear before the leaves, the leaves generally with 3 primary veins at the base; staminate flowers usually in clusters, the pistillate solitary or few together in the axils of the leaves, and near the end of the twigs; fruit a globose drupe, sometimes elongated, pulp thin and sweet, frequently remaining on the tree until late winter, relished by birds; stone bony, wrinkled.

Some of the American species of hackberry are very variable. The habitat of the species varies from deep swamps to arid rocky slopes. In fact, a single species as now understood may have a variable habitat. The following variations may be noted on the same tree or on different trees of the same species. The twigs may be glabrous, or pubescent; the leaves may vary in size, shape and texture, leaf margin, and in the roughness or smoothness of the surfaces; the petioles may be smooth or hairy; the pedicels may be glabrous or pubescent, shorter or longer than the petioles; the fruit also varies in shape. Leaves have been seen on the same tree which were smooth above, while others were quite rough above, the difference being due to the exposure to light.

The original descriptions of the species are too short to sufficiently characterize the species, which adds to the confusion. However, C. S. Sargent[45] has recently revised the species and varieties of our area.

Prof. Sargent has examined and named all of my material for me. Mr. B. F. Bush, who has extensively studied the hackberries in the field, also has examined my specimens.

The writer has paid special attention to the hackberries of the State for the past few years and is still in doubt as to the status of the species that occur in the State. Since I am not following the determinations made by Sargent and Bush, and am following the nomenclature of the first edition, I regard the present treatment as tentative only.

Margins of all the leaves sharply serrate all around except at base; nutlets 6-8 mm. long