732 TREES OF NORTH AMERICA 



XXXIX. TILIACEjE. 



Trees, shrubs, or herbs, with alternate simple leaves, and free stipules. Flowers regular, 

 perfect; sepals valvate in the bud, deciduous; corolla hypogynous; stamens numerous, with 

 2-celled anthers, the cells opening longitudinally; pistil compound; styles united into 1; 

 stigma capitate. Fruit capsular or nut-like. Seeds with albumen; embryo with broad 

 foliaceous cotyledons. 



The Linden family with forty-four 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. TILIAL. Bass Wood. Linden. 



Trees, with terete moderately stout branchlets, without a terminal bud, large compressed 

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

 mucilaginous juice, and tough fibrous inner bark. Leaves conduplicate in the bud, long- 

 petiolate, 2-ranked, cordate or truncate at the oblique base, acute or acuminate, serrale, 

 deciduous, their petioles in falling leaving large elevated horizontal leaf -scars displaying 

 the ends of numerous fibro- vascular bundles; stipules 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 peduncle more or less con- 

 nate 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 or yellow 7 , deciduous; stamens inserted on a short hypogynous receptacle; filaments 

 filiform, forked near the apex, collected into 5 clusters and united at base with each 

 other and (in the American species) with a spatulate 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 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, subglo- 

 bose to short-oblong or ovoid, sometimes ribbed, tomentose, 1-celled by the obliteration of 

 the partitions, 1 or 2-seeded. Seeds obovoid, amphitropous, ascending; seed-coat carti- 

 laginous, light reddish brown; embryo large, often curved, in fleshy albumen; cotyledons 

 reniform or cordate, palmately 5-lobed, the margins irregularly involute or crumpled; radi- 

 cle inferior. 



Tilia with some thirty species is widely distributed in the temperate regions of the north- 

 ern 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 manufac- 

 tured 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 some of 

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

 States. 



CONSPECTUS OF THE SPECIES OF THE UNITED STATES. 



Surface of the leaves glabrous at maturity. 



Leaves glabrous or almost glabrous when they unfold, coarsely serrate. 



Leaves furnished with conspicuous tufts of axillary hairs, their lower surface light 



green and lustrous; pedicels glabrous or nearly glabrous. 1. T. glabra (A). 



Leaves usually without tufts of axillary hairs, their lower surface not lustrous; pedicels 



densely hoary-tomentose. 2. T. nuda (C). 



