202 



BASSWOOD. 



Tilia americana, Linnaeus. 



FAMILY AND GENTJS DESCRIPTION— The Linden family, TiUaceae, comprises about 

 35 genera with probably 375 species found In temperate and tropical regions. The meknbers 

 consist of trees, shrubs, and a few herbs. One genus, Tilia, alone has tree representatives 

 in North America. This genus comprises about 20 species, 'i of which are native to North 

 America and 3 to Pennsylvania. Two species are described here. The third species, known as 

 Michaus's Basswood (Tilia Michausii Nutt.) is very rare in this State. Its leaves which are 

 densely pubescent and grayish-green beneath and its floral bracts usually rounded at the 

 base are distinctive. The bark of the branches is usually smoother and lighter than that 

 of the 2 other native species. 



FORM — A large tree usually attaining a height of GO-70 ft. but may reach a height of 

 120 ft. with a diameter of 45 feet. Trunk straight, clean, with little tain-T. Crown dense, 

 broad, rather deep, ovoid or rounded. 



BARK On old trunks firm but easily rut, thick, longitudinally furrowed into flat ecaly 



ridges. Ridges often divided by transverse fecondary furrows. On young stems dark gray 

 and smooth. See Fig. 79. 



TWIGS — Smooth or very finely hairy, shining, bright red; second year olive, olive-red, or 

 covered with a gray skin: usually zigzag, tough, mucilaginous If chewed, covered with 

 scattered, dark, oblong lenticels. In cross- jeetion, characteristic blunt conical masses with 

 intervening lighter colored areas are present. 



BUDS — Alternate; terminal bud absent; ovoid. 2-ranl;ed, stout, often somewhat flattened. 

 divergent, usually deep red. occasionally greenish, mucilaginous, smooth or sometimes slightly 

 hairy towards apex. Bud-scales glabrous, thick, rounded at back, usually 3 visible; one a 



large scale makes bud unsym metrical. ^ 



LEAVES — Alternate, simple, ovate to orbicular, 4-7 Inches long, firm In teitnre, long- * 



pointed at apex, deeply tocthed on margin with sharp t^rth, unequally heart-shaped to j 



truncate at base, dark green and shining on upper surface, green and smooth on lower except 

 for a few msty hairs. Leaf stalks slender, i length of blade. The side of the leaf nearest 

 the branch is the largest. 



LEAF-SCARS — Alternate, large, conspicuous, raised, 2-ranked, containing few to many 

 bundle-scars arranged in a ring or a single curved line, or scattered. Stipule-scars distinct, 

 one narrow, the other broad; often show bundle-scars. 



FLOWERS — Appear about June. Perfect, regular, sweet, fragrant, yellowish-white, 5-20 Id 

 drooping cymose clusters. The long peduncle which bears the flowers is united for about 

 half its length with a conspicuous green bract. 



FRUIT — A woody, spherical, not-like drupe about the size of a pea. Occurs singly or in 

 small clusters with a common stalk attached to a leafy bract and often persisting far Into 



winter. 



WOOD — Diffuse-porous; rays distinct, but colorless; light, soft, compact, moderately strong, 

 light brown to nearly white, fine in texture; little difference between spring wood and summer 

 wood. Weighs 28.20 lbs. per cubic foot. Used in the manufacture of paper-pulp, wooden- 

 ware, cheap furniture, panels for carriages, kegs, palls, barrel headings, berry boxes. 



DISTINGUISHING CHARACTERISTICS — The Basswood. also known as Linden, Lime-tree, 

 Whitewood. Beetrec, Whistle-wood, and Lynn, may be distinguished by its large, firm nn- 

 equally based leaves with green and smooth lower surfaces, by Its smooth bright red twigs, 

 by its alternate, deep red. unsyrometrical buds with 2-3 visible scales, by its while tlowt-rs 

 arranged in drooping clusters attached to a green bract, and by its woody spherical not-Uke 

 drupe abo'jt the size of a pea attached to winged bracts. The dark funoel-shaj t-d area? in the 

 inner bark alternating with lighter areas as seen in a cross-section of a twig are characteristic. 

 The smooth dark gray bark of younger stems and the thick longitudinally-furrowed bark on 

 older trunks are distinguishing features. 



RANGE — New Brunswick to Manitoba, southward to Georgia and eastern Texas. 



DISTRIBUTION IN PENNSYLVANIA — Common in the eastern and southeastern parts of 

 the State. Rare in the mountainous parts except in rich valleys. Locally abundant in the 

 western part. 



HABITAT — Rarely grows In pure stands, but usually mixed with other hardwoods. Prefers 

 rich soils in bottomlands. It can endure considerable shade. It suffers little from windfall 

 but occasionally from windbreak upon exposed situations. 



mPORTANCE OF THE SPECIES — This tree is one of our important timber trees on ac- 

 count of the valuable wood and the bark which it produces. Seeds or seedlings may be 

 planted. If seedlings are used, they should be planted early In spring before growth starts. 

 The tree sprouts from stump very freely (Fig. 79). It grows rapidly, produces beautiful 

 sweet smelling flowers, and is rarely attacked by fungi. It Is one of our most attractive 

 ornamental trees. 



