Flora of North America species comparison

Dodecatheon hendersonii occurs from southern Vancouver Island in the coastal ranges to west-central California (as far as San Benito County) and is disjunct into the San Bernardino Mountains in southern California. To the east, the species is found on the Siskiyou Mountains and in the Sierra Nevada of California to Tulare County. A Macoun (s.n., DAO) specimen supposedly gathered at Yale, British Columbia, may be misattributed (K. I. Beamish 1955); all other known localities are from Vancouver Island.

Inasmuch as bulblets and mature capsules are rarely collected, it is difficult to clearly distinguish between var. hendersonii and var. hansenii. The former may be broadly characterized as plants bearing bulblets at anthesis with sparsely glandular scapes, pedicels, and, sometimes, calyces. The calyx of var. hendersonii is usually greenish with purple or reddish speckles. The most distinctive characteristics of this phase are a filament tube that is 1–2.5 mm wide and acute anther apices. It is found mainly along the coast from British Columbia to southern Oregon and in scattered locations in coastal California, with disjunct populations in the foothills of the central Sierra Nevada, and in the mountains of southern California. Variety hansenii is glabrous, lacks bulblets, and the calyx typically is green; it usually is found inland in the Siskiyou Mountains and the Sierra Nevada and scattered populations occur in the coastal ranges of northern California. The filaments in var. hansenii are broader, being tubes 1.5–4 mm wide, and anther apices are obtuse. Capsules of var. hendersonii are usually operculate; those of var. hansenii appear to be consistently valvate. The 2n = 66 plants appear to be primarily individuals that produce little or no pollen.

Adding to the complexity is the close association of var. hansenii with Dodecatheon clevelandii var. patulum. The latter, like var. hendersonii, is basically a diploid or a tetraploid (2n = 44, 88), rather than a hexaploid, and one would expect no crossing between the two. Nonetheless, H. J. Thompson (1953) reported finding sterile individuals where D. hendersonii var. hansenii and D. clevelandii var. patulum were in close association. These sterile individuals were morphologically similar to var. hansenii (and not intermediate between the two), and sterile individuals were fairly common in populations of var. hansenii where no other Dodecatheon were present. Although the three entities may be characterized (see table 5 in Thompson), Thompson concluded that assigning names to some populations was difficult and could be established “only by a detailed consideration and summation of all the characters.”

H. J. Thompson (1953) recognized Dodecatheon hansenii; A. F. Cholewa and D. M. Henderson (1993) accepted only D. hendersonii. In their molecular study, A. R. Mast et al. (2004) considered the two entities distinct, albeit closely related, species. It is possible that var. hansenii had a hybrid origin involving var. hendersonii and D. clevelandii var. patulum, and backcrossing with var. hendersonii resulting in a series of morphological features that allies the hansenii phase more to D. hendersonii than to D. clevelandii. More study is needed, especially in areas where the two appear to have overlapping ranges in the Bay Area and Sierra Nevada foothills of California.

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

Dodecatheon meadia is widespread and highly variable. Many segregate species and infraspecific entities have been proposed. Except for recognizing D. frenchii (a diploid), partitioning D. meadia (a tetraploid) into finer units as done by N. C. Fassett (1944) is unrealistic. It has been traditional to distinguish at least two varieties. The typical variety is mainly a plant of the north and east with anthers 6.5–10 mm, capsules 10–18(–21) mm, calyx lobes 4–8 mm, and corolla lobes 12–20 mm. To the south and west (mainly Missouri, eastern Oklahoma, eastern Texas, and Arkansas to northwest Alabama, Tennessee, and Virginia) plants with anthers 4–7(–8) mm, capsules 7–10 mm, calyx lobes 3–5 mm, and corolla lobes 10–15 mm occur; these have been termed var. brachycarpum. A distinction is not made here because both entities are sometimes found growing together, and each can be found, often as individual plants, well outside its expected range. Flower color varies in a different pattern. Most of the southern populations of D. media have white petals; those of the north (including the Linnaean type) have lavender to magenta petals. Throughout the range, petals are sometimes more pinkish or are white with a tinge of purple. In southern Missouri and northern Arkansas are plants with alabaster white petals. All too often, a single population will vary in petal color, making a taxonomic distinction dubious. Plants with ovoid capsules 9–10 × 4–9 mm occur in Alabama; these were named var. obesum Fassett. Although the ovoid condition appears to be restricted geographically, it is doubtful that it diagnoses a well-marked variety.

Dodecatheon meadia is locally common in some areas; on its geographical edges, it is often rare and thus of local concern to some state heritage programs. The species is commonly cultivated and numerous cultivars have been developed.

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