Taxon Details

Malacothamnus lucianus

Arroyo Seco bushmallow

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Taxon Summary:

Malacothamnus lucianus, commonly known as Arroyo Seco bushmallow, is a perennial deciduous shrub in the Malvaceae that is found only in California. It occurs within Chaparral, Cismontane woodland, and Meadows and seeps, growing at elevations from 5 to 915 meters. Malacothamnus lucianus is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification

Scientific Name: Malacothamnus lucianus (Kearney) K. Morse
Common Name: Arroyo Seco bushmallow
Family:	Malvaceae
Element Code:	PDMAL0Q0B2
USDA Plants Symbol:
Synonyms/Other Names: Malacothamnus palmeri (S. Watson) Greene var. lucianus Kearney
Name Status:	JEF, FNA, POWO, IPNI, Tropicos

Conservation Status

CA Rare Plant Rank:	1B.2
Fed List:	None
State List:	None
Global Rank:	G1Q
State Rank:	S1
Other Status:	BLM_S; SB_CalBG/RSABG; SB_SBBG; USFS_S
CRPR Changes:
Add Date:	1974-01-01
Date Edited:	2025-10-29

Ecology and Life History

Lifeform: perennial deciduous shrub

Blooming Period: (Apr)May-Aug

Elevation:
5 - 915 meters
15 - 3000 feet

General Habitats:

Chaparral
Cismontane woodland
Meadows and seeps

Microhabitat Details:

Microhabitat:

Notes

Notes: See Leaflets of Western Botany 7(12):289-290 (1955) for original description.
Threats: Threatened by road maintenance.
Taxonomy: A synonym of M. palmeri in TJM (1993) and of M. palmeri var. palmeri in TJM 2; observations by field botanists suggest that recognition is warranted.

Threat List Data from the CNDDB

THREAT LIST:
Threat List Total:	6
	Total EOs	% of EOs
EOs with Threat Listed:	4	44 %
Altered flood/tidal/hydrologic regime	1	11%
Erosion/runoff	1	11%
Grazing	1	11%
Non-native plant impacts	1	11%
Other	1	11%
Road/trail construction/maint.	1	11%

Occurrence Data from the CNDDB

Element Occurrence Ranks:
Total Occurrences:					9
A	B	C	D	X	U
0	3	0	2	0	4

Occurrence Status:
Historical >20 Years	4
Recent <=20 Years	5

Presence:
Presumed Extant	9
Possibly Extirpated	0
Presumed Extirpated	0

Location

California Endemic:

California Island:

States: Name (Code)
California (CA)

California Counties and Islands: Name (Code)
Monterey (MNT)

Quads: Name (Quad Code)
Big Sur (3612137), Cone Peak (3612114), Junipero Serra Peak (3612124), Lopez Point (3612115), Partington Ridge (3612126)

Notes:

Definitions of codes following a county and/or quad:
*		Presumed extirpated
(?)		Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.

Regional Map

Map

Presumed Extant

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CNPS Rare Plant Inventory