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 phylogenetic 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 mostly distinct from eastern American species. California holds a wide variety of species whose forms are distinctive in leaf and bulb coat 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-F are found on this wiki page.
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. Photos 1-2 were taken by Mary Sue Ittner of plants growing on Figueroa Mountain in Santa Barbara County.
Allium dichlamydeum E. Greene grows near the coast in Northern and central California. The inflorescence is medium pink. Contributor RH notes "[the] bulb is white - not grey-brown with zig-zags (as noted by Dilys Davies)". The Flora of North America describes the bulbs as having a herringbone pattern, see the Flora's description of Allium dichlamydeum. Also see bulb photo at the bottom of the page, the zigzag/herringbone pattern may not be readily apparent to the naked eye and may only be visible with a hand lens.
Since they grow on cliff faces where there is little soil, their bulbs do not bury very deep. It is one of the latest blooming of the Californian onions. These pictures by Bob Rutemoeller show it growing on the Mendocino Sonoma Coast 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.
Photo 1 below shows the plants growing in a raised bed in Mary Sue Ittner's garden. Photos 2-3 by Mark McDonough show two views of this species growing in his Massachusetts garden. Photos 4-6 were taken by Nhu Nguyen of plants growing in a small pot in California. The bulbs divide well and produces a wonderful show.
Photos below by RH. Photos three and four originally obtained as Allium falcifolium. Photo four shows flowers going over and becoming pointier as they wilt, this had created some confusion for the grower.
Photo of bulbs by Ken Gilliland.
Allium douglasii is native to Washington and northeastern Oregon. This variable species prefers vernally wet soil in shallow depression or moist slopes. Photos by Richard Haard.
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 photo by Jane McGary, 2nd by Mary Sue Ittner, and the last a macro of a specimen grown by Nhu Nguyen.
Habitat photos from Nhu Nguyen are shown below. Photos 1-2 shows the habitat in Napa County where they flower with Eschscholzia caespitosa amongst the serpentine rocks. Photo 5 illustrates the sickle shaped leaves.
Allium fimbriatum var. mohavense is only found in the Mohave Desert. It has flowers that are white to pink to light lavender.
Allium fimbriatum var. purdyi is restricted to serpentine soil in the inner North Coast ranges (Colusa, Glenn, Lake, Napa counties). Flowers are white to pale lavender with darker midveins. The first three photos were taken by Nhu Nguyen. The second photo shows developing into seeds and the third photo shows a serpentine slope where they occur.
Photos below were taken by Mary Sue Ittner. The first three were taken along Bear Valley Road in April different years. They were growing along the bank next to the road. The last shows flowers of plants grown from seed collected in Lake Co. at 2150' in crumbly, flaky serpentine talus flats.
Allium index - Allium flavum Relatives - American alliums A-B - American alliums C - American alliums G-H - American alliums I-M - American alliums N-R - American alliums S-Z - 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