Tilia americana L.

• Authority

  Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

• Family

  Malvaceae

• Scientific Name

  Tilia americana L.

• Description

  Species Description - Tree to 40 m; lvs broadly ovate to subrotund, mostly 7–15 cm, sharply serrate, cordate or truncate at base; pet narrowly oblong to oblanceolate, 7–12 mm, tapering to the base; fr subglobose, 6–8 mm; 2n=82. Rich woods; N.B. to Man., s. to Fla. and Tex.; disjunct in Mex. July. Four vars., two with us. The mainly northern var. americana, American b., extending to s. to nw. N.C. and e. Okla., has the lvs green beneath and glabrous to sparsely stellate- hairy (or more densely so when young), commonly with conspicuous tufts of hairs in the vein-axils beneath. (T. neglecta, an introgressant toward the next var.) The mainly s. Appalachian var. heterophylla (Vent.) Loudon, white b., extending n. to sw. Pa. and s. O., w. to s. Ill., with outliers n. and w., is more hairy, the lvs permanently covered beneath with fine white or brown stellate hairs. (T. heterophylla; T. michauxii; T. monticola; T. pubescens)

• Discussion

  Two European spp. with mostly smaller (5–10 cm) lvs and without staminodes escape locally from cult. T. platyphyllos Scop. has strongly 5-ribbed frs, whereas T. cordata Mill. has the frs only weakly or scarcely ribbed.