Double Cone Quarterly
Fall Equinox 2003-- Volume VI, Number 2

Mentzelia laevicaulis
(Blazing Star)
By David Rogers

Blazing Star

Text by David Rogers, photographs by Boon Hughey


Ranking among the showiest-flowered of the native plants of the Santa Lucia Mountains are these perennial herbs of sandy and/or rocky areas, summer-dry flood plains, washes and sometimes road cuts. What first catches the eye are the large five petaled flowers, which are light yellow. and range from about 6 to 16 cm (2.5-6.5") wide when fully expanded. The flowers are further adorned by a wide fountain-like display of numerous long stamens. The five innermost stamens, which alternate with the petals, have widened, petal-like filaments. The plants begin to produce flowers around June and continue to do so until about October. Another striking feature of this species are the whitish-shining stems. Although Mentzelia laevicaulis translates as "smooth-stemmed Mentzelia," this is in comparison to other Mentzelia species, for at least the upper stems are rough to the touch due to a light coat of short and stiff barbed hairs.

Mentzelia laevicaulis is widely distributed in temperate western North America, where it is occurs suitable habitats in California, Nevada, Oregon, Washington, British Columbia, Idaho, Montana, Wyoming and Utah. It is found in diverse regions, ranging from lowland deserts to mountainous areas up to about 2700 m. (8,000'). In California it is present in all of the geographical regions of the state except for the Central Valley and the Sonoran Desert. Although Mentzelia laevicaulis usually occurs in interior regions, it reaches within at least 3 linear miles of the ocean in the Santa Lucia Mountains, as evidenced by the accompanying photographs by Boon Hughey. Boon took these photos near Lottie Potrero Camp, which is located in the headwaters region of San Carpofóro Creek. San Carpofóro Creek drains a large area on the coastal slopes of the Santa Lucia Mountains.


This species was first named in the journals of David Douglas, the well-known Scottish botanical explorer of western North America and the Hawaiian Islands during the 1820s and 1830s. Douglas first encountered this species "on the gravelly islands and rocky shores of the Columbia [River], near the 'Great Falls.'" Douglas named it Bartonia laevicaulis, and this was the name used in the first published description of the species, which was in Sir William Hooker's "Flora Boreali-Americana." Although the final edition of Hooker's text was published in 1840, the section in which the description of this species was described was first published in 1834. As "Bartonia" had previously been applied to a genus belonging to a different family, it was invalid for plants belonging to Loasaceae, the family to which Mentzelia belongs. This problem was corrected in 1840, when John Torrey & Asa Gray's "A Flora of North America" was published. This text reduced the Loasaceae "Bartonia" plants to synonymy with Mentzelia (Darlington).

The earliest botanical specimen of Mentzelia laevicaulis from the Santa Lucia Mountains may have been the one that was included in a large number of specimens that Reason Alpha Plaskett sent to Alice Eastwood in 1898. Eastwood, the curator of the California Academy of Sciences Herbarium at that time, was hosted by the Plaskett family, an exceptionally large family of early settlers in the Pacific Valley area of the Big Sur coast, on two of her expeditions to the Santa Lucia Mountains in the 1890s.

Mentzelia laevicaulis

Mentzelia laevicaulis is a perennial herb according to some texts, while others state that it is a biennial or short-lived perennial. The stems, which are generally erect and usually begin to branch above the middle, range from about 22 to 100 cm. (9-40") tall. As stated above, the stems and branches are white-shining and at least the upper stems have a light coat of short barbed hairs. The leaves are lobed and are also covered with short barbed hairs; those at the base of the plant range from about 19-24 cm. (7.5-9.5") long, while the upper leaves, which are alternate, range from about 2-10 cm. (.8-3") long. The flowers, which are subtended by bracts, are singular or in groups of two to three at the end of the branches; the lance-shaped sepals are about 15-46 mm. (.7-2") long, while the petals, which are also lance shaped, range from about 3 to 8 cm. (1.3-3.25") long. The numerous long stamens are produced in four to five series, and as stated above, the five innermost stamens have broadened filaments that somewhat resemble petals. There is only one long style, which represents the outermost (terminal) portion of the flowers. The ovaries are inferior, and the fruit is a subcylindric capsule about 15 to 44 mm. long. The winged seeds are about 2 to 3 mm. long.


As stated above, the genus Mentzelia belongs to the Loasa Family (Loasaceae), which is comprised of 15 genera and about 200 species chiefly of the Americas, but also of Africa and Pacific Islands. Mentzelia is comprised of about 50 species of the Western Hemisphere, and is particularly well represented in Western North America (and especially in California, where 28 of the 50 species are present). The genus was named by Carolus Linnaeus (Carl von Linne, 1707-1778), the founder of binomial nomenclature and the sexual system of classification, for Christian Mentzel (1622-1701), a seventeenth century German botanist.

The other Mentzelia species of this region are M. gracilenta Torrey & Gray, M. veatchiana Kellogg, M. affinis E. Greene, M. dispersa Watson and M. micrantha (Hooker & Arnott) Torrey & Gray. All of these are annuals and all have flowers that are much smaller than those of M. laevicaulis. Only the flowers of M. gracilenta (with petals .7-1.8 cm. long) can be described as showy, for the remaining species have petals ranging from 2 to 10 mm. long, and the very small flowers of M. micrantha are often obscured by their subtending bracts. The following plate of illustrations of the local Mentzelia species are from Leroy Abrams' "Illustrated Flora of the Pacific States:"


Although the preceding illustration of M. micrantha looks more like the plants that I have observed in the Santa Lucia Mountains, I have decided to include the following illustration of this species from Willis L. Jepson's "A Manual of the Flowering Plants of California" (1925), for it also depicts bugs (look closely) that have gotten hooked on the barbed hairs that are typical of Mentzelia species. This morphological adaptation is a defense against predation by insects.



Abrams, Leroy. Illustrated Flora of the Pacific States, vol. 3: 134-141. Stanford University Press, Stanford, CA. 1951.

Darlington, Josephine. A Monograph of the Genus Mentzelia. Annals of the Missouri Botanical Garden 21: 103-226. 1934.

Hitchcock, C. Leo., and Arthur Cronquist. Vascular Plants of the Pacific Northwest, vol 3: 455-456. University of Washington Press, Seattle. 1961.

Hooker, Sir William Jackson. Flora Boreali-Americana, vol. 1; 221. (1834) 1840. Reprinted in 1960 by H. R. Engelmann (J. Cramer) and Wheldon & Wesley, Ltd.

Howitt, Beatrice, and John Thomas Howell. The Vascular Plants of Monterey County. The Wasmann Journal of Biology, vol. 22 (1). 1964. Supplement to the Vascular Plants of Monterey County. Pacific Grove Museum of Natural History Association, Pacific Grove, CA. 1973.

Matthews, Mary Ann. An Illustrated Field Key to the Flowering Plants of Monterey County, and Ferns, Fern Allies and Conifers. California Native Plant Society, Sacramento. 1997.

Munz, Phillip, in Collaboration with David Keck. A California Flora (1959), with Supplement (1968). University of California Press, Berkeley, Los Angeles and London.

Prigge, Barry, in James Hickman, ed. Loasaceae in the Jepson Manual, Higher Plants of California. University of California Press, Berkeley Los Angeles and London. 1993.