Asclepias speciosa

showy milkweed, milkweed

Family:Apocynaceae

Rarity

CNPS-EB: B

9 current natural populations

Criteria:

S Limit

Observations

CNPS-EB Database ⓘ
Calflora (group) ⓘ
Calflora (public)
iNaturalist
- Genus Asclepias
- Asclepias speciosa
CCH2

Key

Ecology

Flowers May - September

Habitats:

Miscellaneous

All Asclepias

A. cordifolia (A2)
A. eriocarpa (A1)
A. speciosa

References

Synonyms

Asclepias giffordii

Populations

Key

Location	Pop ID	Last Recorded	Notes
Bollinger Canyon Rd - N of Crow Canyon Rd	2	2004-09-11
Briones Rgnl Park	3	2021-03-02
Kennedy Grove Rgnl Park	11	2025-07-02
Las Trampas Rgnl Wilderness	9	2023-05-29
Las Trampas Rgnl Wilderness	10	2025-06-29
San Antonio Reservoir - SFWD	6	2004-06-02
San Leandro Reservoir - EBMUD	1	2014-06-12
San Leandro Reservoir - EBMUD	4	2024-05-01
San Pablo Ridge Area	7	2012-07-28
Garin/Dry Creek Rgnl Park - unknown which park	8	1995-12-31	ID Uncertain
San Leandro Reservoir - EBMUD	5	1993-12-31	Historic

The list of populations shows the distinct populations identified by the CNPS-EB Rare and Unusual Plants Committee. The locations in this list are very general. More specific location details can be obtained from the links in the Observations section (for some of these links, a login is required).

Font

Populations in bold type have precise coordinates available for field volunteers and researchers.

Populations in normal type are only known from a description of the location; no precise coordinates are available.

Background

Populations with a white background have been observed in the last 25 years.

Populations with a blue background have not been observed for at least 25 years.

Populations with an orange background have an uncertain location or identification, or are planted.

Columns

Pop ID is a label that identifies the population. Many locations have more than one population of a species, and the population ID is used to distinguish them.