3346 



TILIA 



TILIA 



drooping clusters followed by small inconspicuous 

 nutlets. The species in cultivation are nearly all hardy 

 North and not particular as to the soil, but do not thrive 

 well in dry locations or in dry climates. They are much 

 planted as shade and ornamental trees and, particularly 

 in Europe, are favorite avenue and street trees. The 

 best for avenue planting are T. tomentosa, T. euchlora, 

 T. americana, T. cordata; T. tomentosa stands heat and 

 drought better than any of the others, while T. platy- 

 phyllos, although often planted for its rapid growth, is 

 likely to suffer in dry seasons or in dry localities. 



Propagation is by seed which must be sown soon after 

 ripening or stratified, as it does not germinate until the 

 second year if kept dry and sown in spring. Also 

 increased by layers; in layering usually the method of 



3811. Tilia platyphyllos. 



"stooling" is employed; this consists of cutting a 

 younger tree close to the ground and of laying down and 

 covering partly with earth the numerous shoots which 

 will appear. Varieties or rarer species are often grafted 

 in spring or budded in August on common stock. Plants 

 raised from layers or grafts remain often one-sided for 

 many years, as the lateral branches usually employed 

 for propagation have the tendency to grow horizontally 

 instead of strictly upright. 



INDEX. 



KEY TO THE SPECIES. 



A. Lvs. green or glaucous^ beneath, glabrous 



cr pubescent with simple hairs. 

 B. Under side of Ivs. and branchlets pu- 

 bescent: fls. without staminodes. . . 

 BB. Under side of Ivs. glabrous except 



axillary tufts of hairs. 

 c. Axillary tufts present at the base 



of the If. and elsewhere. 

 D. Margin of Ivs. finely serrate: fls. 



without staminodes. 

 E. Lvs. green beneath; the tertiary 

 veins prominent. 



1. platyphyllos 



P. Upper surface of Its. dull 

 green, margin with short- 

 pointed teeth 2. vulgaris 



FF. Upper surface glossy dark- 

 green, margin with long- 

 pointed teeth 3. euchlora 



EE. Lvs. glaucous beneath; the ter- 

 tiary veins not prominent. 

 F. Cymes 5-11-fld.: fls. with- 

 out staminodes 4. cordata 



FF. Cymes 8-40-fld.: fls. with 



staminodes 5. japonica 



DD. Margin of Ivs. coarsely serrate, 

 Ivs. often S-lobed: fls. with 



staminodes 6. mongolica 



cc. Axillary tufts of hairs wanting at 

 the base, present elsewhere: Ivs. 

 4~5^in. long: fls. with stami- 

 nodes 7. americana 



AA. Lvs. with stellate hairs or stellate tomen- 



tum beneath: fls. with staminodes. 

 B. Branchlets glabrous. 



c. Axillary tufts of hairs present on 

 the grayish green or grayish 



under side of the Ivs 8. neglecta 



cc. Axillary tufts of hairs wanting, 



under side white or whitish. 

 D. Under side of Ivs. densely white- 



tomentose. 



E. Size of the ovate or ovate- 

 oblong Ivs. 4~? i n -i margin. 



sharply serrate 9. heterophylla 



EE. Size of the orbicular-ovate Ivs. 

 2-4 in., margins sinuately 



serrate 10. Oliveri 



DD. Under side of Ivs. thinly grayish 

 tomentose or stellate-piibescent, 

 usually with long hairs on the 



veins 11. spectabilis 



BB. Branchlets pubescent. 



c. Without axillary tufts of hairs on 



the Ivs. beneath. 

 D. Shape of Ivs. orbicular-ovate, the 



white tomentum persisting. 

 E. Tomentum of branchlets, 

 buds, and petioles grayish 

 or whitish; margin of Ivs. 

 finely serrate with short- 

 pointed teeth. 



F. Habit upright: petioles 

 shorter than half the blade: 



fr. slightly 5-angled 12. tomentosa 



FF. Habit pendulous: petioles 

 longer than half the blade: 



fr. 5-furrowed 13. petiolaris 



EE. Tomentum of branchlets, buds, 

 and petioles yellowish or 

 brownish: margin of Ivs. 

 coarsely serrate with long- 

 pointed teeth 14. mandschurica 



DD. Shape of Ivs. ovate or triangular- 

 ovate: Ivs. irregularly and 

 coarsely serrate with short- 

 pointed teeth, often glabrescent 



with age 15. Miqueliana 



cc. With axillary tufts of hairs; Ivs. 

 orbicular-ovate, grayish - tomen- 

 tose beneath, brownish on midribs 



and nerves 16. Maximowic- 



[ziana 



1. platyphyllos, Scop. (T. grandifolia, Ehrh. T. 

 europasa, Linn., in part). LARGE-LEAVED LIME. Fig. 

 3811. Tree, to 120 ft.: young branchlets pubescent, 

 older glabrous: Ivs. orbicular-ovate, abruptly acumi- 

 nate, obliquely cordate at the base, regularly serrate, 

 dull green and short-pubescent or glabrous above, light 

 green and pubescent beneath, 3-4 in. long; petioles 

 stout, hairy: fls. in usually 3-fld. pendulous cymes; 

 petals oblanceolate, longer than sepals; stamens 30; 

 style glabrous: fr. globose, ovoid or pyriform, 3-5- 

 ribbed, apiculate, tomentose, thick-shelled. June; the 

 earliest species to bloom. Eu. G.F. 2:256 (adapted in 

 Fig. 3811). H.W. 3:42, p. 24, 25. R.F.G. 6:316, 317, 

 318. Very variable; some of the most important varie- 



