TÍLIA. The Basswoods.

Trees with medium sized twigs; leaves alternate, mostly taper-pointed, oblique cordate or truncate at the base, serrate; flowers in axillary or terminal cymes, white or yellow, fragrant, peduncles of the cymes with a leaf-like bract adhering to about half their length; fruit nut-like, woody, 1-celled.

1. Tilia glÀbra Ventenat (Tilia americana LinnÆus of authors). Linn. Basswood. Plate 118. Medium to large sized trees with deeply furrowed bark, much resembling that of white ash or black walnut; twigs when chewed somewhat mucilaginous, usually somewhat zigzag; leaves on petioles 2-6 cm. long, blades ovate to nearly orbicular, 5-15 cm. long, short or long acuminate at the apex, margins more or less coarsely or finely serrate with teeth attenuate and ending in a gland, dark green and smooth above, a lighter green and generally smooth beneath at maturity except tufts of hairs in the axils of the principal veins, or sometimes with a scanty pubescence of simple or stellate hairs beneath; flowers appear in June or July, when the leaves are almost mature; bracts of the peduncles very variable, generally about 8-10 cm. long, rounded, or tapering at the base, obtuse or rounded at the apex, smooth both above and beneath at maturity; peduncles from very short up to 6 cm. in length; pedicels of flowers variable in length on the same and on different trees, generally about one cm. long; styles pubescent near the base on all of the specimens at hand; fruit woolly, globose or somewhat ellipsoidal, generally about 6 mm. in diameter.

Distribution.—New Brunswick to Manitoba, south to Georgia and west to Texas. More or less frequent to common in rich moist soil in all parts of Indiana. It is the most frequent and common in the lake area of the State but was almost as frequent and common throughout the central part of the State until the hilly area is reached where its habitat disappears for the greater part. In the hill area it is confined to the basins of streams, although sometimes found on the high rocky bluffs of streams. Rare or absent in the flats. In most of its area it is associated with white ash, slippery elm, beech, maple, shellbark hickory, etc.

Remarks.—Wood soft, light, straight and close-grained, white and seasons well. On account of its softness and lightness it has always been a favorite wood where these two factors were important considerations. Is practically odorless, hence, is a desirable wood to contain food products. Its principal uses are lumber, heading, excelsior and veneer. The supply of this species in Indiana is now practically exhausted.

Plate 118

In Indiana this species is commonly called linn, and only in a few counties near the Michigan line is it known as basswood. The name basswood is a corruption of the name bastwood, meaning the inner tough and fibrous part of the bark, which was used by pioneers for tying shocks of corn, and other cordage purposes. However, Dr. Schneck gives the name whittle-wood as one of its common names; and in some localities it is called bee tree, because bees find its flowers rich in honey.

Linn is adapted to a rich moist soil, transplants fairly well, and grows rapidly. It has been used to some extent as an ornamental and shade tree, but its use as a street shade tree is no longer recommended because it is not adapted to city conditions, and is killed by the scale. It could, however, be recommended as an integral part of a windbreak, or woodlot where the land owner has an apiary.2. Tilia heterophylla Ventenat. Linn. White Basswood. Plate 119. Usually large trees; bark similar to the preceding but lighter in color; twigs similar to the preceding species; leaves on petioles 2-8 cm. long, blades ovate to nearly orbicular, generally 7-15 cm. long, generally oblique at the base, oblique-truncate or cordate at the base, abruptly short or long acuminate at the apex, margins serrate with teeth attenuate and ending in a gland, at maturity smooth and a dark yellow-green above, the under surface generally densely covered with a silvery or gray tomentum, however, on some specimens the pubescence is thin and appears as a stellate pubescence, the tufts of hairs in the principal axils of the veins are reddish brown, in addition to the pubescence reddish glands are often found on the veins beneath; flowers appear in June or July when the leaves are almost mature; bracts very variable. 4-15 cm. long, generally on short peduncles, rounded or wedge-shape at the base, generally rounded at the apex, sometimes merely obtuse, glabrous both above and below, or more or less densely pubescent beneath and generally sparingly pubescent above; pedicels of flowers variable in length, usually about 1 cm. long; styles of flowers pubescent at the base; fruit globose or somewhat ellipsoidal generally 6-8 mm. in diameter.

Distribution.—This species as understood by Sargent ranges from West Virginia to Indiana and south to Florida and west to Alabama. In Indiana it is confined to counties near the Ohio River. Specimens are in the writer's herbarium from Dearborn, Ripley, Switzerland, Jefferson, Clark, Harrison, Crawford, Perry, southeastern Dubois and east Spencer Counties. Practically in all of its range in Indiana it is found on the tops of high bluffs along streams or on the slopes of deep ravines. It is an infrequent to a common tree where found. In general in the counties just mentioned it supplants the other species of Tilia. It was reported from Wayne County by Phinney, and Schneck says a single tree was found near the mouth of White River. The last named tree may be Tilia neglecta which is said to be found just west in Illinois.

Plate 119

Remarks.—Wood and uses similar to that of the preceding species. In Indiana the species are not commercially separated.

A satisfactory division of the species of Tilia of the United States has long been a puzzle. C. S. Sargent[65] has recently published his studies of the species and credits Indiana with two species and one variety. His range of Tilia neglecta might include a part of Indiana, and it may be that the pubescent forms of Tilia glabra in our area should be referred to that species. Specimens No. 28043 and 28047 in the writer's herbarium collected from trees on the high bluff of Graham Creek in Jennings County, Sargent refers to Tilia heterophylla variety Michauxii Sargent. While Sargent's key to Tilia quite distinctly separates the species and varieties, yet when specimens are collected from an area where the species overlap and seem to intergrade, the task of referring a specimen to the proper species or variety is not an easy one. In fact the writer acknowledges his inability to satisfactorily classify our forms of Tilia, and the present arrangement should be accepted as provisional.