This eastern tree is widespread in most regions of Ky., but much less frequent on the more fertile base-rich soils. It was virtually absent in original woods of the central Bluegrass region (Campbell 1989). Variation needs further study. Some narrow-leaved colls. from CALL may be referred to var. caroliniana (Poir) Fern., but that taxon is not recognized in recent treatments. See also notes under biflora. N. sylvatica is often associated with Acer rubrum, from dry to wet habitats, but it tends to be concentrated in areas with more history of disturbance, including fire. Young growth is susceptible to browsing by ungulates, but resprouting can be vigorous, and from spreading roots in some cases. Distinction of this species from Diospyros virginiana is sometimes difficult without flowers or fruits. As detailed by W (see also Y etc.), Nyssa leaves differ as follows: three vascular bundle per scar (versus one); petioles and midrib above lacking small reddish to blackish glands, becoming necrotic spots (versus present); blades often with a few irregular teeth (versus never toothed), pale to medium green beneath (versus whitish especially when dried), and glabrous or nearly so below (versus glabrate to tomentose with curly hairs). Also, blade shape is generally narrower (with L/W mostly 2-2.5 versus 1.7-2.1), usually with narrowly to broadly cuneate base (versus truncate to subcordate), and veins are generally opaque to bright light (versus often translucent, at least secondary veins when fresh). Buds are ovoid with several scales (versus bluntly to sharply pointed wth 2 main scales or sometimes with 1-2 extra apical scales).