Arctostaphylos regismontana
NATIVE – CA ENDEMIC
Description (Jepson, PlantID.net)
- Eudicotyledon
- Eudicots are a major lineage of flowering plants; see family for general characteristics
- Heath Family (Ericaceae)
- Large, erect evergreen shrub
- Base of shrub lacks a burl (technically a lignotuber: a woody swelling of the root crown with numerous buds and food reserves), found in some manzanita species
- Stems
- Glandular (sticky), hairy twigs (young stems)
- Smooth reddish-brown bark, often with distinctive peeling
- Leaves
- Alternate (1 leaf at each junction with stem) and simple (not divided into leaflets)
- Overlapping (imbricate) and clasping the stem
- Edges smooth or sharply toothed
- Glandular, hairy, and sticky (smooth in age)
- Dull gray-green on both sides
- Oblong to ovate (boat-shaped), up to 2.4 in.
- Deeply lobed at base (auriculate)
- Pointed tip
- Flowers
- Inflorescence (flower arrangement) a panicle (branching stem with flowers opening from the bottom up)
- White to pinkish bell- or urn-shaped flowers
- Ovary superior (above the attachment of other flower parts)
- Fruit is a red drupe (a fleshy fruit with usually 1 seed in a hard inner shell – a stone fruit)
- Shaped like a small apple with dimples at top and bottom
- Glandular and hairy
- Height to 16 ft.
Distribution
- Native and endemic (limited) to California
- Grows in chaparral and in broadleaf and coniferous forests on granite and sandstone soils
- See Calflora for statewide observations of this plant
- California Rare Plant Rank: 1B.2 (rare, threatened, or endangered in California and elsewhere)
- Grows at elevations between 490 and 2,560 ft.
Uses (San Mateo County Parks prohibits removal of any natural material)
- Wildlife
- Birds and mammals eat the stony fruit: birds poop out the seeds, but mammals can crack the stone and eat the nutritious embryo (Kauffmann 2015)
- Larval food source (host) for the western brown elfin butterfly (Callophrys augustinus iroides)
- Native people (Anderson 2005)
- Fruit was eaten fresh or used for making tea, cider, or jellies
- Stems were used for making fire drills
- Bushes were actively managed by pruning and burning, stimulating many positive effects
- Vigorous and straighter shoots
- Larger and more numerous fruits
- Less congested canopies
- Reduced insect infestations
- Recycled nutrients
Name Derivation
- Arctostaphylos (ark-toe-STAF-i-los) – from the Greek words arktos, “bear,” and staphule, “a bunch of grapes,” perhaps suggesting that bears eat the grape-like fruits; sometimes translated “bear berry”
- regismontana (REJ-is mon-TAY-na) – refers to Kings Mountain in San Mateo County
- Manzanita – from the Spanish for “little apple”
Adaptations
- Manzanita species are adapted to survive frequent and intense fires (Kauffmann 2015)
- Species without burls (two thirds of manzanita species, including Kings Mountain manzanita) regenerate from dormant seed banks (obligate seeders) in the first year after a fire
- Seeds require smoke and other fire conditions for germination
- Species with burls (one third of manzanita species) regenerate by vegetative re-sprouting and from seed (facultative seeders)
- Seeds are cached in the soil by mammals, such as rodents, at a depth that protects them from high fire temperatures
- Mammals are the primary seed dispersers of manzanitas
- Species without burls (two thirds of manzanita species, including Kings Mountain manzanita) regenerate from dormant seed banks (obligate seeders) in the first year after a fire
- Adapted to survive seasonal and periodic drought
- Glandular hairs on the leaves of some species, like Kings Mountain manzanita, capture moisture from rain, dew, or fog
- Leaf orientation also helps conserve water
- Most species, like Kings Mountain manzanita, hold their leaves vertically to lower leaf temperatures and have stomata (small openings for exchange of water vapor, carbon dioxide, and oxygen) on both sides of the leaf
- Other species, like brittle-leaved manzanita (A. crustacea ssp. crustacea), also at Edgewood, hold their leaves more horizontally and have stomata only on the more protected lower leaf surface
Notes
- Pollinated most effectively by sonication or “buzz pollination”; see Heath family for details
- Manzanitas are major components of California chaparral
- Chaparral refers to evergreen shrub and small tree communities that grow on shallow, rocky, nutrient-poor soils in Mediterranean climates, with mild, wet winters and hot, dry summers
- California hosts 58 of the 60 manzanita species in the world
- The majority are local endemics, with distribution areas less than 20 square miles, and most of these grow near the Pacific coast (Kauffmann 2015)
- Alice Eastwood (1859-1953), who headed the Department of Botany at the California Academy of Sciences for 50 years, named a quarter of California’s manzanita species and altogether named nearly 400 plant species (Ritter 2018)
- Kings Mountain manzanita is 1 of 3 closely-related rare species on the peninsula that were previously all classified as Santa Cruz manzanita (A. andersonii)
- Montara Mountain manzanita (A. montaraensis) grows in northern San Mateo County, centering around Montara Mountain
- Kings Mountain manzanita (A. regismontana) grows in central San Mateo county, centering around Kings Mountain
- Santa Cruz manzanita (A. andersonii) grows in southern San Mateo County and in Santa Cruz and Santa Clara Counties
- In 2009, a single Franciscan manzanita (A. franciscana), a species believed to be extinct in the wild for almost 70 years, was spotted in the median strip of Doyle Dr. by a keen-eyed botanist driving home; because the location was an active construction site, a large-scale, carefully-coordinated effort was successfully made to transplant the 18 ft. wide, low-growing shrub to an undisclosed Presidio location (Quirós 2011)
- Why does Edgewood have so few individual manzanita plants — just one Kings Mountain manzanita bush and a few brittle-leaf manzanitas (A. crustacea ssp. crustacea) — compared to Pulgas Ridge Open Space Preserve, which is just to the north and has a large colony of brittle-leaf manzanitas?
- Manzanitas, like other members of the Heath family, thrive in well-drained, acidic soils, like sandstones
- Edgewood has only a few areas with sandstone soils; you can find a small strip of Whisky Hill sandstone on the eastern border of the preserve
- Pulgas Ridge Open Space Preserve has a large amount of Whiskey Hill sandstone (Heiple 2020)
- Manzanitas, like other members of the Heath family, thrive in well-drained, acidic soils, like sandstones
ID Tips
- At Edgewood, Kings Mountain manzanita may be confused with 2 other members of the Heath family with peeling, reddish bark
- Brittle-leaved manzanita (A. crustacea ssp. crustacea)
- Pacific madrone (Arbutus menziesii)
| Brittle-leaf Manzanita | Kings Mountain Manzanita | Pacific Madrone | |
| Growth Habit | shrub | tree-like shrub | tree |
| Height | ≤ 10 ft. | ≤ 16 ft. | ≤ 130 ft. |
| Burl | yes | no | yes; usually underground |
| Leaves | |||
| Shape | base not lobed — ~2 in. long | base deeply lobed — ~2 in. long | base not lobed — ~5 in. long |
| Orientation | not overlapping — held horizontally | overlapping — held vertically | not overlapping — held horizontally |
| Hairs and Glands | |||
| Leaves | not hairy or sparsely only on underside — not glandular (sticky) | often hairy — often glandular (sticky) | not hairy — not glandular (sticky) |
| Twigs | hairy — not glandular (sticky) or sparsely | hairy — glandular (sticky) | not hairy — not glandular (sticky) |
| Fruits | not hairy — not glandular (sticky) | hairy — glandular (sticky) | not hairy — not glandular (sticky) |
| Trails | lower Old Stage Rd. | Sunset Trail | most woodland trails |
At Edgewood
- Found in woodlands
- Edgewood hosts only one Kings Mountain manzanita shrub, located near the north end of the Sunset trail
- No iNaturalist observations are documented because locations of rare species are obscured
- Flowers February – April
Specific References
Anderson, M.K. 2005. Tending the Wild. University of California, Berkeley. Pp. 137; 274-280.
Alice Eastwood. Circa 1910. California Academy of Sciences. Public Domain.
Heiple, P. 2020, Jan. 27. Personal communication.
Kauffmann, M., T. Parker, and M. Vasey. 2015. Field Guide to Manzanitas: California, North America, and Mexico. Backcountry Press, Kneeland, California.
Quirós, G. 2011, Jan. 19. 15 months later, rediscovered San Francisco plant thrives. KQED Quest.
Ritter, M. 2018. California Plants: A Guide to Our Iconic Flora. Pacific Street Publishing, San Luis Obispo, California.
Shapiro, A.M. and T.D. Manolis. 2007. Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions. University of California Press, Berkeley and Los Angeles, California.