Large deciduous trees. Twigs moderate, smooth, zigzag; pith continuous,pale. Buds solitary, obliquely sessile, rather large, inequilaterally ovoid, with about 2 green or red scales; terminal bud lacking. Leaf-scars alternate, 2-ranked, somewhat raised, half-elliptical; bundle-traces 3 or compound and scattered; stipule-scars unequal. Winter characters of the two principal native species are closely similar, but the withered leaves are usually present and diagnostic.
Fig, 219. Tilia americana.
Fig. 220. Tilia heterophylla.
Leaves essentially the same color on both surfaces; northern species
Leaves whitened beneath; southern species
1. T. americana L. American Linden. Basswood. A large tree up to 40 m. high; bark gray, furrowed; twigs glabrous, green; fruit globose, 6-8 mm. in diameter. Rich woods, Quebec to Manitoba, south to Tennessee, Arkansas, and Texas (Fig. 219).
2. T. heterophylla Vent. White Basswood. White Linden. Linn. A large tree, 20-30 m. high, with a diameter of 1. 5 m. ; bark at first gray and smooth, becoming furrowed into flat ridges; twigs glabrous, reddish or yellowish-brown; fruit ellipsoid, 8 mm. long. Rich woods, Florida to Alabama and Missouri, north to West Virginia and New York (Fig. 220).