Flora of North America species comparison

The pine lily’s flower is the largest of any North American lily and one of the largest among our native monocots. In small plants it dwarfs and sometimes topples the slender stem. Leaves are small and relatively few and the bulb is petite, and thus resource limitation in smaller plants undoubtedly contributes to the wide range of fruit sizes within populations. In other North American members of the genus, small plants produce one or a few capsules, but typically these approach normal size.

Lilium catesbaei subsp. asprellum Wherry and L. catesbaei var. longii Fernald have been proposed to account for individuals with leaves concentrated toward the middle of the stem or somewhat wide and lacking basal leaves, respectively. These variants are not emphasized here since both are based primarily on vegetative features that vary greatly in most lilies. Isotypes of var. longii are unremarkable, though with somewhat wide leaves, and the broadly overlapping distribution of this variety with nominate populations (A. E. Radford et al. 1968) strongly suggests that such differences are primarily environmentally induced. Variety longii was described from Virginia, and Fernald’s observation that these northern plants lack basal leaves—which I have not investigated in the field—is unsurprising in those colder climates, and best considered in terms of the normal variation within a fairly wide-ranging species.

Although it is not yet rare, widespread alteration of native longleaf pine (Pinus palustris Miller) and slash pine (P. elliottii Engelmann) savanna, especially conversion to even-age pine plantations, is making steady inroads on populations of this most beautiful lily. It is adapted to frequent fires, and their suppression may contribute to this decline.

Lilium catesbaei is pollinated primarily by the palamedes swallowtail [Papilio palamedes (Drury), family Papilionidae], the only swallowtail that is widely endemic to this lily’s coastal plain habitat. Spicebush swallowtails (P. troilus Linnaeus) visit the pine lily less frequently, and their smaller size suggests that they are less effective pollinators than the larger palamedes.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Throughout most of modern botanical history this Chinese lily has been known as Lilium tigrinum, but recent nomenclatural reassessment affirms that Thunberg’s description, published sixteen years earlier than Ker Gawler’s, applies to this species. Though many North America species are known vernacularly as tiger lilies, the name is properly applied only to this one. Along with L. candidum, it is considered to be among the earliest domesticated lilies (H. D. Woodcock and W. T. Stearn 1950), no doubt because it is handsome, easy to grow, and the bulbs are edible and substantial. It is widely planted in North America, usually as a sterile triploid that is best propagated from the bulbils.

Perhaps the hardiest garden lily, Lilium lancifolium is a widespread but sporadic garden escape, and roadside lilies near habitation in eastern and northeastern North America are often this species. Despite its general use in gardens, it seems to be naturalized only in the better-watered eastern portion of the continent.

In North America, the tiger lily is rather easily diagnosed by its truly lanceolate and widely sessile alternating leaves that bear dark bulbils on the upper stem. The mature buds are usually high-shouldered and taper rather evenly to a flattish apex with three greenish, terminal, rounded processes. No native lily consistently displays any of these features.

(Discussion copyrighted by Flora of North America; reprinted with permission.)