670 TREES OF NORTH AMERICA 



The Linden family with about thirty-five genera is chiefly tropical, with 

 more representatives in the southern than in the northern hemisphere. Of the 

 three North American genera only Tilia is arborescent. 



1. TILIA, L. Linden. 



Trees, with terete moderately stout branchlets, without terminal buds, large com- 

 pressed acute axillary buds, with numerous imbricated scales, those of the inner 

 rank accrescent, mucilaginous juice, and tough fibrous inner bark. Leaves condu- 

 plicate in the bud, long-petiolate, 2-ranked, cordate or truncate at the oblique base, 

 acute or acuminate, serrate, deciduous, their petioles in falling leaving large elevated 

 horizontal leaf-scars displaying the ends of numerous fibro-vascular bundles; stip- 

 ules ligulate, membranaceous, caducous. Flowers nectariferous, fragrant, on slender 

 clavate pedicels, in axillary or terminal cymes, with minute caducous bracts at the 

 base of the branches, their peduncles more or less connate with the axis of a large 

 membranaceous light green ligulate often obovate persistent conspicuously reticulate- 

 veined bract; sepals 5, distinct; petals 5, imbricated in the bud, alternate with the 

 sepals, sometimes thickened and glandular at the narrow base, creamy white, decid- 

 uous; stamens inserted on a short hypogynous receptacle; filaments filiform, forked 

 near the apex, collected into 5 clusters and united at the base with each other and (in 

 the American species) with a spatidate petaloid scale (^staminodium) placed opposite 

 each petal, the branches of the filament bearing oblong extrorse half anthers; ovary 

 sessile, tomentose, 5-celled, the cells opposite the sepals; style erect, dilated at the 

 apex into 5 spreading stigmatic lobes; ovules 2 in each cell, ascending from the 

 middle of its inner angle, semianatropous, the micropyle centripetal-inferior. Fruit 

 nut-like, woody, subglobose to short-oblong or ovoid, sometimes ribbed, tomentose, 

 1-celled by the obliteration of the partitions, 1 or 2-seeded. Seeds obovate, semi- 

 anatropous, ascending ; seed-coat cartilaginous, light reddish brown; embryo large, 

 often curved, in fleshy albumen; cotyledons reniform or cordate, palmately 5-lobed, 

 the margins irregularly involute or crumpled; radicle inferior. 



Tilia with eighteen or twenty species is widely distributed in the temperate re- 

 gions of the northern hemisphere with the exception of western America, central 

 Asia, and the Himalayas. Tilia produces soft straight-grained pale-colored light 

 wood, largely used for the interior finish of buildings, in cabinet-making, for the 

 sounding-boards of pianos, wood-carving and wooden ware, and in the manufacture 

 of paper. The tough inner bark is largely manufactured into mats, cords, fish-nets, 

 coarse cloths, and shoes. Lime-flower oil, obtained by distilling the flowers of the 

 European species, is used in perfumery. The flowers yield large quantities of nectar, 

 and honey made near forests of Tilia is unsurpassed in flavor and delicacy. Many of 

 the species are planted as shade and ornamental trees, and several of the European 

 species are now common in the gardens and parks of the eastern United States. 



CONSPECTUS OF SPECIES OF THE UNITED STATES. 



Branchlets g-labrous. 



Leaves glabrous. 



Leaves green on both surfaces. 1. T. Americana (A, C). 



Leaves pale on the lower surface. 



Peduncles and pedicels glabrous ; staminodia entire ; leaves mostly cordate at the 

 base. 2. T. australis (C). 



