On these pages photos of North American Allium species will be featured. There are approximately 130 taxa in North America, almost half of which occur in California as the center of diversity. Besides a few species that are widely grown, namely Allium cernuum (nodding onion), the Californian A. unifolium (popularized by the Dutch bulb trade) and the lesser known A. stellatum (prairie onion), the North American onion species have been largely ignored by the horticultural world. There are also about 15 species native to Mexico, similarly rare or absent from horticulture. Eastern American species generally need a cool - cold winter dormancy period with some to lots of rain. Western American species, especially those in the Pacific States follow a Mediterranean pattern where they need a moderately cold wet winter and a cool dry summer.
Taxonomically, there have been few changes in American species. A recent phylogentic study by Nguyen et al., 2008 found that North American alliums are distinct from European species and those occurring in the 
California Floristic Province (CFP) are distinct from eastern American species. California holds a wide variety of species whose forms are distinctive in leaf morphology. Species related to Allium falcifolium form falcate leaves whereas species related to Allium jepsonii form a single leaf from which the inflorescence emerges on the side. Many CFP species have also adapted to a special type of soil called serpentine which is very high in minerals such as magnesium, making it toxic to many plants. Some Allium species are so adapted that they can only be found on serpentine soil in the wild.
American alliums from D-H are found on this wiki page. American alliums A-C – American alliums I-M – American alliums N-R – American alliums S-Z
Allium diabolense (syn. Allium fimbriatum var. diabolense) is a California species found south of San Francisco Bay in the Inner South Coast ranges where it is often found growing in serpentine. It has white flowers with pink midveins and one leaf. These plants were seen growing on Figueroa Mountain in Santa Barbara County and although I am not certain, from a process of elimination of other species found in this spot, I believe they are this species. First two photos by Mary Sue Ittner, last two by Nhu Nguyen.
Allium dichlamydeum - grows near the coast in Northern and central California. Since they grow on cliff faces where there is little soil, their bulbs do not bury very deep. These pictures by Bob Rutemoeller show it in bud on a coastal bluff, in bloom in the same spot a few weeks later, and a close-up. The fourth picture shows it growing in a wild rock garden where it would be difficult for predators to get it, and almost two months after the first pictures in mid July 2003 it is still in bloom, now with Dudleya farinosa blooming at the same time. The final picture is a close-up of the two plants in bloom in another year.
The next group of photos show it first growing in a raised bed in Mary Sue Ittner's garden and in the last two photos by Mark McDonough two views of this species growing in his Massachusetts garden.
Allium eulae (synonym A. fraseri var. eulae), is native to Texas where it is endemic to the Texas Highland Lake region, growing in seepy places, although hardy in more northern climates and growing well in normal well drained garden soil in full sun. Photo by John Lonsdale.
Allium falcifolium - occurs on serpentine soils and outcrops from San Francisco Bay to Oregon. It is often found on slopes with excellent drainage. It is also never found too far away from oak trees, relying on the organic matter from decaying oak leaves. The hummus contents can range from 50% - 20% in the wild. There are two flower forms of this species, with the more common magenta pictured below and a more rare and often elusive white form. 1st photos by Jane McGary, 2nd by Mary Sue Ittner, and the rest by Nhu Nguyen. The 2nd photo illustrates the sickle shaped leaves and the bud as well as open flower. The 5th photo shows the habitat where they flower with Eschscholzia caespitosa. The 6th photo is also taken in habitat showing the species growing among the rocks. The last photo is a macro of a specimen grown by Nhu Nguyen.
Allium fimbriatum - There are three varieties of the species, A. fimbriatum var. fimbriatum, A. fimbriatum var. mohavense and A. fimbriatum var. purdyi. Variety purdyi is restricted to serpentine soil (and is pictured here). The species is restricted to California where they grow on dry, well-drained slopes. The second photo shows developing into seeds and the third photo shows a serpentine slope where they occur. Photos by Nhu Nguyen.
Allium glandulosum - a Mexican species that blooms in late summer and autumn with dark, metallic red flowers. The plant shown here in several photos was originally collected in central Mexico at high elevation in swampy soil. Difficult to photograph well and I'm sorry about the poor shots. The first two show the true red flowers close up, the last shot show an entire potted plant. Photos by Mark McDonough.
Allium gooddingii - another of the moisture-loving western species, this one from Arizona and New Mexico, growing at high elevation swampy or marshy spots, or alongside streams. It's a slender plant, with a few-flowered upright spray of intense red-purple flowers. The gray stems reach about 18" (45 cm). In the photo we see the gray foliage of A. plummerae in back and a flower head of A. flavum. Photo by Mark McDonough.
Allium haematochiton is found both on dry slopes and ridges from the south coast ranges of California into northern Baja, but also is found in seasonally moist, grassy meadows. It is tolerant of summer water and almost evergreen in those conditions. If dormant it is one of the first to appear in the fall and long blooming. It is also known to grow on serpentine. Photos by Bob Rutemoeller and Kristina Van Wert from the Mendocino Coast Botanical Gardens collection.
The pictures listed below were taken at Figueroa Mountain April 2005 by Mary Sue Ittner.
The pictures below are grown and photographed by Nhu Nguyen. The second photo shows the blood-red skin of the bulbs, giving it the specific epithet "haematochiton" or "red tunic" in Greek.
Allium hickmanii is restricted to the central coast of California from the Monterey Peninsula to San Luis Obispo County. It is a relatively small onion with very thin leaves. It grows on grassy, wooded slopes. Photos by Nhu Nguyen.
Allium hyalinum is another California onion with small starry flowers that sparkle. It is found in grasslands moist in the spring in the central and southern Sierra foothills. There are generally two forms, a white and a pink. Photos by Bob Rutemoeller and Kristina Van Wert from the Mendocino Coast Botanical Gardens collection. The last photo shows the pink form grown and photographed by Nhu Nguyen.
Allium index – American alliums A-C – American alliums I-M – American alliums N-R – American alliums S-Z – Allium flavum Relatives – Allium hybrids – Big Ball alliums – Blue alliums – chives – Domed alliums – Drumstick alliums – Miscellaneous alliums A-E – Miscellaneous alliums F-M – Miscellaneous alliums N-R – Miscellaneous alliums S-Z – Rhizomatous alliums
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