Flora of North America species comparison

Subspecies 5 (5 in the flora).

The subspecies of Lilium pardalinum display a classic pattern of discrete geographical ranges with intervening zones of introgression, and no two occur sympatrically without intermixing. Plants in the hybrid zones are confusing in appearance and cannot be assigned to subspecies. However, each subspecies is fairly well marked within its core distribution. With the exception of subsp. pitkinense, the subspecies of L. pardalinum can be common plants in the proper habitats within their rather narrow distributions.

Leaf size and shape are quite variable in Lilium pardalinum subspecies and often clearly dependent on environment. In populations that typically have narrow, ascending leaves, shaded plants often have wide, horizontal leaves. This hampers taxonomic separation as well as identification, especially of herbarium specimens. Further field study is desirable.

Lilium pardalinum is primarily pollinated by western tiger swallowtails (Papilio rutulus Lucas, family Papilionidae) and pale swallowtails (P. eurymedon Lucas); several species of hummingbirds (family Trochilidae) are also important visitors, especially when butterflies are rare.

The Atsugewi, Karok, and Yana ate Lilium pardalinum bulbs steamed or baked in an earth oven (D. E. Moerman 1986).

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

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.)