1918] SARGENT—TILIA 423, 
Leaves hoary tomentose when they unfold. 
Leaves soon glabrous. 
Leaves coarsely serrate with stout teeth, their veinlets conspicuous; 
branchlets stout, bright fea) 6 ys eee on 3. T. venulosa 
Leaves finely serrate with straight or incurved teeth, their veinlets less 
conspicuous; branchlets slender, pale reddish brown. .4. T. littoralis 
Leaves crenately serrate, glaucescent on the lower surface 
5 creno-serraia 
Leaves covered below early in the season with articulate bates: becoming 
glabrous or nearly glabrous. 
Leaves thin, coarsely serrate, green or glaucescent on the lower surface, 
with or without tufts of axillary hairs; summer shoots not pubescent 
6. T. floridana 
Leaves subcoriaceous, finely serrate, bluish green and lustrous below 
vate in the season; ig of axillary hairs minute, aad wanting; 
Or SEEM DUCED bo ee eee ee 7. I. Cocks 
Surface of the leaves pubescent ue during the seaso 
Lower surface of the leaves covered with sane tes ‘feisty attached pubes- 
cence; tufts of axillary hairs not conspicuous............. 8. T. neglecta 
Lower surface of the leaves covered with eee easily rachel hairs. 
Branchlets without straight hairs. 
Leaves ovate, acuminate, usually obliquely truncate at base, glabrous 
above, their pubescence brownish or white........ 9. T. caroliniana 
Leaves oblong-ovate, cordate or obliquely cordate at some pubescent 
above ently in the sengon. 6 6 cee eas ot. te 
Leaves semiorbicular to broadly ovate, a or point, deeply 
. T. pha 
and usually symmetrically cordate at base.......... phanera 
Branchlets covered with straight hairs; leaves ovate, sbrop short- 
ted, oblique and truncate at base............... . T. lasioclada 
poin 
Surface of sft leaves tomentose below during the season with close firmly 
attached tomentum. 
Tomentum white, gray, or brown; leaves usually glabrous on the upper sur- 
face; branchlets and winter buds glabrous (occasionally pubescent in 
varieties of no 
Branchlets pee td petioles not more than 4 cm. long; leaves oblong- 
ovate, acuminate or abruptly pointed, oblique and truncate or cordate 
at — tomentum on the leaves of upper branches often brown; 
5-5-6 te. We ee eee 13. T. heterophylla 
Shadi stout; petioles up to 7. cm. in length; leaves oblong-ovate, 
acuminate, obliquely truncate at base; tomentum always white; flowers 
SOEs TT On a ek ed eek ee 14. T. monticola 
Tomentum pale or brownish; leaves thickly covered above early in the 
season with Fscicied hairs; ‘bruichiels tomentose; winter buds pubescent 
15. T. georgiana 
