Arctostaphylos crustacea

Arctostaphylos crustacea, commonly known as brittleleaf manzanita,[2] is a species of manzanita found mostly in the fog belt of the Central Coast of California and the San Francisco Bay Area.[2]

Arctostaphylos crustacea
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Ericales
Family: Ericaceae
Genus: Arctostaphylos
Species:
A. crustacea
Binomial name
Arctostaphylos crustacea
Eastw. (1933)
Synonyms[1]
  • Arctostaphylos glandulosa subsp. crustacea

Description

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Arctostaphylos crustacea resprouting from a burl

Plants of this species are generally shrubs of up to 3 m (9.8 ft) in height,[3] with smooth, reddish bark,[4] and ovate leaves that are 2–5 cm (0.79–1.97 in) long.[3]

This species, unlike many others manzanitas, has bifacial leaves, leaves which mostly only have stomata on their lower surface. [5] Fruits of this species are depressed-globose (shaped like a squashed sphere) drupes which contain multiple separate nutlets. The flowers are urn-shaped and grow on multi-branched panicles. [3][5] Plants of this species, like some others in the genus Arctostaphylos, have a burl at their base from which they resprout from after the shrub is top-killed by fires.[2]

Taxonomy

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This species used to be part of the Arctostaphylos tomentosa complex, but was split in 2007. [4] Below is a list of subspecies:

 
Image of leaf of A. c. crustacea. Note the mostly-hairless underside of the leaf
  • Arctostaphylos crustacea subsp. crinita — This subspecies has hairy twigs with long and short bristles, with the lower side of its leaves covered with dense hairs. It is found in the southern Santa Cruz Mountains and some isolated parts of the Central Coast. [4]
 
Image of leaf of A. c. crinita. Note the tomentose hairs on the underside of the leaf.
  • Arctostaphylos crustacea subsp. eastwoodiana — This subspecies has twigs that are hairy but without long bristles and leaves with glabrous undersides.[4] It has a very limited range, found in western Santa Barbara County near Lompoc, mostly on substrate derived from siliceous rocks,[3] twigs hairy but without long bristles. [4]
  • Arctostaphylos crustacea subsp. insulicola — This subspecies has twigs that are hairy but without long bristles and leaves with hairy undersides.[4] It's found on Santa Rosa and Santa Cruz Islands, mostly on substrate derived from volcanic rocks.[4]
  • Arctostaphylos crustacea subsp. rosei — This subspecies has twigs that are hairy but without long bristles and leaves with glabrous undersides.[4] Its range is very fragmented, only being found in small specific areas from San Francisco to Monterey County.[2]
 
Image of leaf of A. c. rosei. Note the lack of hairs on the leaf underside and the lack of long bristles on the petiole.

References

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  1. ^ Adams, Joseph Edison (May 10, 1935). A Systematic Study of the Genus Arctostaphylos (PhD thesis). University of California Graduate Division. OCLC 18236502.
  2. ^ a b c d Kauffmann, Michael; Parker, Tom; Vasey, Michael (2015). Field Guide to Manzanitas. Backcountry Press. ISBN 978-1-941624-02-9.
  3. ^ a b c d Wells, Philip V. (2000). Manzanitas of California: Also of Mexico and the World. P.V. Wells. ISBN 0-933994-22-2.
  4. ^ a b c d e f g h i Parker, V. Thomas; Vasey, Michael C.; Keeley, Jon E. (April–June 2007). "Taxonomic Revisions in the Genus Arctostaphylos (Ericaceae)". Madroño. 54 (2): 148–155. doi:10.3120/0024-9637(2007)54[148:TRITGA]2.0.CO;2. JSTOR 41425696.
  5. ^ a b "Arctostaphylos crustacea". Flora of North America. Oxford University Press. September 29, 2009. Retrieved October 20, 2024.