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Allium sharsmithiae

An Allium endemic to the Mount Hamilton Range in California, this rare bulbiferous perennial features a 5–50-flowered umbel with deep reddish-purple tepals, inhabits serpentine soils on talus slopes at 400–1,200 m and flowers in April–May, with global rank G2, California rarity 1B.3, and BLM status.

Is Allium sharsmithiae growing in your garden? Record it and all of your plants in Known.

Common Names

Sharsmith's Onion, Helen Sharsmith's Onion, Mount Hamilton Onion

Summary

Sharsmith's onion is a perennial bulbous herb endemic to California, confined to serpentine soils in the Mount Hamilton Range where it grows in Chaparral and Cismontane woodland at 400–1,200 m in rocky microhabitats. Bulbs are solitary and 1–2 cm in diameter; leaves are basal and wither from the tip by anthesis; the flowering stalk is erect to about 20 cm tall and supports a hemispheric umbel of 5–50 flowers; flowers are urn-shaped with deep reddish-purple tepals and yellow anthers.

Conservation status is California Rare Plant Rank 1B.3, global rank G2, state rank S2, known from about 9 occurrences; habitat and distribution are limited, with threats including mining, road and trail construction and maintenance, feral pigs, and over-collecting, and it occurs on serpentine soils in the Mount Hamilton Range.

Lifecycle

Perennial

Height

6-8 inches

Soil Type

Serpentine soils

Bloom Color

Deep reddish-purple

Bloom Time

Spring

Leaf Lifecycle

Semi-deciduous

Seasons of Interest

Spring (Apr–May)

Propagation Methods

Bulb propagation (bulbs/offsets)

Taxonomy

Taxonomic Rank
Species
Author
(Ownbey & Aase ex Traub) McNeal
Publication
Aliso 13: 417 (1992)

Superior Taxa

Kingdom
Plantae
Subkingdom
Pteridobiotina
Phylum
Angiosperms
Order
Asparagales
Family
Amaryllidaceae
Genus
Allium

Synonyms

Allium fimbriatum var. sharsmithiae

References

Allium sharsmithiae - FNA. floranorthamerica.org.
Allium sharsmithiae. rareplants.cnps.org.
Allium sharsmithiae. calphotos.berkeley.edu.
Flora of North America species comparison. northwestwildflowers.com.
USDA Plants Database. plants.sc.egov.usda.gov.
Allium sharsmithiae (Ownbey & Aase ex Traub) McNea…. powo.science.kew.org.
Allium sharsmithiae. rareplants.cnps.org.
Allium sharsmithiae. rareplants.ebcnps.org.
Allium sharsmithiae. species.data.kew.org.
Allium sharsmithiae Calflora. calflora.org.
Sharsmith's onion (Allium sharsmithiae) · iNatural…. inaturalist.org.
World Flora Online. worldfloraonline.org. June 2024.