Flora of North America species comparison

Subspecies 2 (2 in the flora).

Lilium humboldtii is declining throughout its range due to habitat destruction, primarily for housing. Forming large scattered colonies at foothill elevations under ponderosa pines or in oak canyons and chaparral, these massive plants with towering inflorescences and large flowers are quite striking. With Lilium pardalinum and L. parryi, they were used in the early part of the century to produce the Bellingham hybrid lilies, development of which continued with the Bellmaid hybrids. Though not as popular as various Asiatic hybrids, these are still in use.

A. M. Kellogg was aware as early as 1859 that the tall, orange-flowered, dry-land lily from the foothills of the Sierra Nevada was distinctive, and he presented this opinion to the California Academy of Sciences about that time (A. M. Kellogg 1872). By the time he had published a description attached to the name Lilium bloomerianum, P. E. S. Duchartre had described this same plant from material provided by B. Roezl and grown by M. Leichtlin, and named it after the German explorer and botanist Alexander von Humboldt. Carl Purdy and others then misapplied Kellogg’s name in various combinations to the southern California expression recognized here as Lilium humboldtii subsp. ocellatum.

The Humboldt lily is pollinated primarily by large butterflies, especially western tiger swallowtails (Papilio rutulus Lucas, family Papilionidae) and pale swallowtails (P. eurymedon Lucas), and to a lesser extent by the monarch butterfly [Danaus plexippus (Linnaeus), family Nymphalidae].

(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.)