Common Names

Bishop, pricklecone, dwarf marine, Obispo, umbrella (Peattie 1950) or Santa Cruz Island pine (Little 1980).

Taxonomic notes

Syn: Pinus edgariana Hartweg 1848; P. muricata var. anthonyi Lemmon 1892; P. muricata var. borealis Axelrod nom. inval. (holotype not cited); P. muricata var. stantonii Axelrod nom. inval. (holotype not cited); P. remorata H. Mason 1930; P. muricata var. remorata (H. Mason) Silba; P. muricata f. remorata (Mason) Hoover (Millar 1986, Kral 1993).

Trees with small symmetrical cones, found mainly toward the southern end of the species' range, are sometimes treated as P. remorata, but analysis by Hoover (1966) showed this character to be inconsequential; he treated it as a forma, the lowest rank of botanical recognition. The earliest name at varietal rank for trees with small symmetrical cones is Lemmon's var. anthonyi, a name overlooked by many subsequent authors.

Trees in the north of the range differ in having glaucous foliage and a taller, narrower crown habit; see further under Remarks, below.

"The several varieties described for Pinus muricata reflect the high variability in leaf characters and in degree of elaboration of apophysis and umbo in this species. The extremes can sometimes occur together" (Kral 1993).

Description

Tree: Height to 24 m; trunk to 90 cm dbh, straight to contorted, crown rounded, flattened, or irregular (Kral 1993).
Bark: Dark gray, deeply furrowed, ridges long, scaly-plated (Kral 1993).
Branches: Spreading-ascending, often contorted (Kral 1993).
Shoots: Stout to slender, orange-brown, aging darker brown, rough (Kral 1993).
Leaves: Two per fascicle, spreading to upcurved, persisting 2-3 years, 8-15 cm × (1.2-)1.5(-2) mm, slightly twisted, dark yellow-green (glaucous blue-green in northern populations), all surfaces with stomatal lines, margins strongly serrulate, apex abruptly conic-acute; sheath to 1.5 cm, base persistent. Buds ovoid-cylindric, dark brown, 1-2.5 cm, resinous (Kral 1993).
Cones: Maturing in 22-24 months, serotinous, persisting for up to 70 years (or more; longer than any other pine), mostly in whorls, mostly asymmetric, lanceoloid-ovoid before opening, curved-ovoid when open, 4-9 cm, rich glossy chestnut-brown, sessile or on stalks to 2-4 mm long, mostly downcurved (Kral 1993, M.P. Frankis e-mail Mar-1999).
Cone scales: Have a deep red-brown* border distally on adaxial surface; apophyses usually much thickened (but not on symmetrical cones), the abaxial ones progressively more angulately dome-shaped toward base of cone; umbo central, a stout-based, curved claw (Kral 1993).
* This border (the sealing band) is yellow-brown on freshly opened cones, darkening through orange and deep red-brown to deep purple on exposure to light and/or oxygen over a year or so in the herbarium; same colour changes on e.g. P. radiata, P. attenuata, etc. (M.P. Frankis e-mail Mar-1999).
Pollen cones: Ellipsoid, to 5 mm long, orange (Kral 1993).
Seeds: Obliquely ellipsoid; body 6-7 mm, dark brown to near black; wing 15-20 mm. 2n=24 (Kral 1993).
Wood:
Similar species:

Range

USA: Coast of C and N California, and Santa Cruz and Santa Rosa Islands; Mexico: Baja California Norte, locally on the mainland, also on Isla Cedros in SW Baja California Norte (Silba 1986). See also Thompson et al. (1999). Habitats include dry ridges to coastal, windshorn forests, often in or around bogs; at 0-300 m elevation. The species is rare enough to be of conservation concern (Kral 1993).

Big Tree

Diameter 139 cm, height 34 m, crown spread 12 m. Locality: Mendocino County, CA (American Forests 1996).

Oldest

Dendrochronology

Ethnobotany

Observations

Can be seen along the northern end of Inverness Ridge at Point Reyes National Seashore.

Remarks

The numerous cones remain closed, even when enveloped by the wood of the growing trunk. The common name is derived from the pine's 1835 discovery near the mission of San Luis Obispo in Alta California (Little 1980).

"The species P. muricata is quite variable in terms of morphological, genetic, geographical, physiological, ecological and chemical characteristics. Research by Millar (1983, 1986) and Lloyd (1975) has attested to a steep cline within the species. Pinus muricata is divided into four varieties [not all validly published; see taxonomic notes, above]: muricata, borealis, remorata, and cedrosensis. The differences between the varieties are based on tree size, foliage, bark, and cones. Millar (1983) states that in northern California, a continuous population extends 180 kilometers from Ft. Ross to Ft. Bragg with several morphological and biochemical characteristics changing abruptly at Sea Ranch (27 km north of Ft. Ross). The northern population is called the blue strain (due to the blue colored cast to the foliage) and the southern population is called the green strain (due to deep green foliage). The differences in the strains are related to stomatal anatomy, waxiness of needles, monoterpene composition, allozymes, and the flowering phenology. It is thought that the evolution of these different strains is due to population biogeographic movement and adaptation to unique soils. Millar (1986) felt that sufficient allozymic variation exists to encourage isozyme analysis for further genetic studies with Bishop pine" (Trees of California website).

The northern 'blue' trees, probably distinct at subspecific rank or even a separate species, are without a scientific name; Axelrod's [invalid] var. borealis was described from Salt Point, Sonoma Co., about 20 km south of the southernmost 'blue' trees at Sea Ranch, on the Coast Hwy at the Annapolis road junction. They have proved impossible to hybridise with the typical 'green' trees in controlled experiments. (Millar 1983, 1986; Millar and Critchfield 1988; Millar et al. 1988).

The northern 'blue' trees have shown promise as a potential timber tree in Britain and New Zealand, with growth rates of up to 2m/year when young even on very poor sandy soils.

This species is listed as endangered by the Mexican government (NOM-ECOL-059-94).

In its native range, this species is a principal host for the dwarf mistletoe Arceuthobium littorum (Hawksworth and Wiens 1996).

Citations

Hoover, R.F. 1966. Miscellaneous new names for California plants. Leafl. West. Bot. 10: 337-338.

Millar, C.I. 1983. A steep cline in Pinus muricata. Evolution 37: 311-319.

Millar, C.I. 1986. The Californian closed-cone pines; a taxonomic history and review. Taxon 35: 657-670.

Millar, C.I. and W.B. Critchfield. 1988. Crossability and relationships of Bishop Pine. Madroño 35: 39-53.

Millar, C.I., S.H. Strauss, M.T. Conkle and R.D. Westfall. 1988. Allozyme differentiation and biosystematics of the Californian closed-cone pines. Systematic Botany 13: 351-370.

See Also

Farjon and Styles 1997.

FEIS database.

This page co-edited with M.P. Frankis, Mar-1999.