Pinus coulteri D.Don

  • Authority

    Farjon, Aljos K. & Styles, Brian T. 1997. Pinus (Pinaceae). Fl. Neotrop. Monogr. 75: 1-291. (Published by NYBG Press)

  • Family

    Pinaceae

  • Scientific Name

    Pinus coulteri D.Don

  • Type

    Type. United States. California: Santa Lucia Mtns. near Cone Peak. 1832-1833, T. Coulter s.n. (holotype, TCD, only an ovuliferous cone).

  • Synonyms

    Pinus ponderosa subsp. coulteri (Lamb. ex D.Don) A.E.Murray

  • Description

    Species Description - Tree, medium size, height to 15-25 m, dbh to 100 cm. Trunk monopodial, straight or curved at base. Bark on the lower part of the trunk 3-5 cm thick, rough, scaly, divided into irregular, longitudinal plates and deep, longitudinal fissures, dark brown with black fissures, on young trees scaly, reddish brown or greyish brown. Branches of first order very long, thick, spreading horizontally to more or less ascending, usually persistent along much of the trunk; branches of higher orders sparse, spreading, assurgent or ascending, ultimate branches very thick, upturned, forming a broad, irregular-pyramidal and open crown. Shoots multinodal, thick, rigid, rough with prominent, decurrent pulvini, light orange-brown or purplish brown, often glaucous. Cataphylls large, 15-20 mm long, subulate, recurved, with caudate apex and erose-ciliate margins, orange-brown with darker apex, caducous. Vegetative buds large, the terminal buds 15-30 mm long, ovoid-acute, the laterals ovoid, smaller, resinous, reddish brown, with imbricate, subulate-caudate scales (as cataphylls). Fascicle sheaths thick, ca. 20 mm long, with ca. 8 imbricate, yellowish white scales, persistent, remaining long, weathering scarious, grey. Leaves in fascicles of 3, in dense tufts at the ends of upturned branches, spreading, persisting 3-4 years, very rigid, straight or curved, slightly twisted, 15-25(-30) cm X 1.9-2.2 mm, margins bluntly serrulate, apex acute-pungent to subulate, light green to grey-green, often very resinous. Stomata on all faces of leaves, with (10-)12-14 lines on the convex abaxial face and (4-)5-7 lines on each adaxial face. Leaf anatomy: Cross section transverse-triangular, with a convex abaxial side; cutícula and epidermis thick; hypodermis multi-layered, pluriform, with intrusions into the mesophyll; resin ducts (2-)3-5, medial, occasionally 1 internal; stele elliptic in cross section; outer cell walls of endodermis not thickened; vascular bundles 2, distinctly separated. Pollen cones in a dense cluster near the proximal end of a new shoot, ovoid to cylindric, 20-25 mm long, light purplish brown, maturing to orange-brown. Microsporophylls with peltate distal part minutely striated radially, darkest in the centre. Seed cones subterminal, at the base of a subsequent leading shoot, solitary or occasionally in pairs, or in whorls of 3-4(-5) on the bole of young trees; borne on thick, short, persistent peduncles, holding the cone to the branch for as long as 25 years (Borchert, 1985) and retaining a few basal scales when it falls. Immature cones (broadly) ovoid, on relatively long, bracteate peduncles; with unguiform umbos strongly incurvate, the proximal umbos recurved, yellowish green, maturing in 16-18 months. Mature cones (narrowly) ovoid, massive, heavy, usually slightly oblique or curved, with a very thick (4-7 cm) woody rachis, moderately serotinous, 20-35 X 15-20 cm when open, extremely resinous. Seed scales ca. 180-220, flat, thick woody with thin, curved margins, widest toward the apophysis, gradually parting over several years, purplish brown on the abaxial side, light brown with conspicuous marks of seed wings on the adaxial side. Apophyses very strongly developed, on one side of the cone larger than on the other, thick woody, sharply transversely keeled, more or less abruptly (or gradually) merging into a long, uncinate umbo, up to 30 mm wide, light yellowish brown or light caramel-coloured. Umbo dorsal, the strongest developed of all pines, elongate, curved, with keeled sides, 25-35 X 10-15 mm at base, ending in a sharp uncinate claw, concolorous with the apophysis or slightly darker. Seeds obliquely obovoid, slightly flattened, 10-18 X 7-10 mm, smooth, lustrous dark brown, turning blackish. Seed wings articulate but effective, held to the seed by two thin, hollow appendages enveloping the seed margins, dolabriform to semi-ovate, (excl. claws) 18-30 X 12-16 mm, orange-brown to dark reddish brown. Cotyledons 9-14.

  • Discussion

    Uses. Pinus coulteri has no particular commercial value as a timber tree and its seeds are not harvested for consumption. In Mexico it rarely forms extensive stands. Locally, some trees may be harvested where they occur nearby or mixed with Pinus jeffreyi, with which Coulter pine may occasionally hybridize (see below).

    This remarkable pine was found in 1832-1833 by Thomas Coulter in the Santa Lucia Mountains, near Cone Peak, California, “within sight of the sea and at an elevation of from 3000 to 4000 feet above its level,” and described by D. Don (1836), together with four other new species of Pinus (one of them now recognized in the genus Abies) found by Coulter in the same general area. The description and plate, which appeared as intercalated material in the third (octavo) edition of Lambert's (1832) Description of the genus Pinus, has been shown to occur only in a few copies of the work and to be of a date after 1836 (Little, 1949), disproving a claim of earlier publication by Keck (1946). Another but unknowing discoverer may have been David Douglas, whose 1831-1832 collections of P. sabiniana appear to have become mixed with specimens of P. coulteri (Griffin, 1964; Little, 1949; see also Lindley, 1840). While Douglas’s specimens were sent to the Horticultural Society of London, those of Coulter were lent to David Don, then librarian with the Linnean Society of London, and in TCD, a cone is kept which is from Coulter's herbarium (Nelson & Probert, 1994: fig. 43); it was used for the illustration of the species in Lambert’s third edition (see above).

    The collections here studied from Baja California Norte do not differ from those originating in the main range of the species in California. Martinez (1948) gave a description for the Mexican pines similar to Krai (1993) for the United States. In the southern Coast Ranges of California, Borchert (1985) reported variation in cone serotiny related to vegetation types, with serotiny being more pronounced in periodically burned communities. This may apply to various populations in Baja California in a similar pattern.

    Natural hybrids have been reported between Pinus coulteri and P. jeffreyi (Zobel, 1951; Critchfield, 1966a) in California. In the Sierra Juárez, both species are sympatric in parts of their ranges, but hybrids seem to be very infrequent (Zobel, 1951) and no examples have come to our attention.

    Distribution and Ecology: United States: Coast Ranges of central and S California, from Contra Costa County south to San Diego County. Mexico: N Baja California Norte. Scattered and rare in the interior Sierra Juárez, isolated in the coastal Sierra Juárez (Sierra Blanca), also scattered and rare in the Sierra San Pedro Martir (Minnich, 1987). In California, Coulter pine is prominent in the southern California Mixed Conifer Forest, especially at the lower limit of this forest type, where it merges into fire-prone chaparral. In Baja California it is also a tree of mixed chaparral, together with Quercus chrysolepis, or growing on granite boulder formations around Laguna Juárez. Its altitudinal range in Mexico is from 1200-1800 m in the Sierra Juárez to 1900-2150 m in the Sierra San Pedro Martir (Minnich, 1987). The climate is of a Mediterranean type with winter rain and long, hot, dry summers. Phenology: Pollen dispersal occurs in May-June.

    Phenology: Time of pollen dispersal varies mainly with altitude and is from March (Critchfield, 1966b) to July.

  • Distribution

    Mexico North America| Baja California Mexico North America|