Ponderosa Pine

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iPonderosa Pine
Pinus ponderosa subsp. ponderosa branch with cones
Pinus ponderosa subsp. ponderosa branch with cones
Conservation status

Least concern (LR/lc)
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Pinaceae
Genus: Pinus
Subgenus: Pinus
Species: P. ponderosa
Binomial name
Pinus ponderosa
Douglas ex C. Lawson
Range map of Pinus ponderosa and Pinus arizonica
Range map of Pinus ponderosa and Pinus arizonica

Ponderosa Pine (Pinus ponderosa) is a widespread and very variable pine native to western North America. See the table below for the botanical characters of the different types.

A mature P. ponderosa subsp. ponderosa with younger individuals
Enlarge
A mature P. ponderosa subsp. ponderosa with younger individuals

In most texts separated into two varieties, modern forestry research has shown that there are four different taxa of Ponderosa Pine, with differing botanical characters and adapted to very different climatic conditions. These have been termed "geographic races" in forestry literature, while some botanists have historically treated them as distinct species. In modern botanical usage, they best match the rank of subspecies, but not all of the relevant botancial combinations have been formally published yet. These are as follows:

Pinus ponderosa was first discovered by David Douglas in 1826 in eastern Washington near where the city of Spokane now lies. This is within the area of the "North Plateau race", and this therefore is the type subspecies.

The distributions of the subspecies, and that of the closely related Arizona Pine (Pinus arizonica) are shown on the map. The numbers on the map correspond to the taxon numbers above and in the table below. The base map of the species range is from Critchfield & Little, Geographic Distribution of the Pines of the World, USDA Forest Service Miscellaneous Publication 991 (1966).

Before the distinctions between the "North Plateau race" and the "Pacific race" were fully documented, most botanists assumed that Ponderosa Pines in both areas were the same. So when two botanists from California found a distinct tree in western Nevada in 1948 with some marked differences from the Ponderosa Pine they were familiar with in California, they described it as a new species, Washoe Pine, Pinus washoensis. However, subsequent research has shown that this is merely a southern outlier of the typical "North Plateau race" of Ponderosa Pine.

The bark of the Ponderosa Pine has a smell similar to vanilla.[1]

[edit] Table of characters distinguishing the subspecies of Pinus ponderosa and Pinus arizonica

 Taxon  1 North Plateau   2 Rocky Mts   3 Southwest   4 Pacific     5 Arizona   6 Storm's 
 Character  (ponderosa  (scopulorum  (brachyptera  (benthamiana    (arizonica  (stormiae
 Needles per fascicle  3  2-3  2-3  3    4-5  3-5
 Needle length  10-22 cm  8-17 cm  12-21 cm  15-30 cm    12-22 cm  20-30 cm
 Needle thickness  1.7-2.2 mm  1.5-1.7 mm  1.6-1.9 mm  1.3-1.7 mm    1.0-1.1 mm  1.0-1.2 mm
 Cone length  5-11 cm  5-9 cm  5-10 cm  7-16 cm    5-9 cm  6-11 cm
 Cone scale width  14-19 mm  16-20 mm  14-19 mm  18-23 mm    15-18 mm  12-17 mm
 Immature cone colour  purple  green  green  green    green  green
 Mature cone surface  matt  matt  glossy  glossy    glossy  matt
 Seedwing to seed length ratio   1.9-2.5  2.1-3.4  3.0-3.5  3.0-4.7    2.8-3.2  3.0-3.5
 Max tree height  50 m  40 m  50 m  70 m    35 m  20 m
 USDA hardiness zone  4  4  6  7    7  8

Notes:
Taxon numbers refer to the map
Needles per fascicle - the most frequent number is in bold
Seedwing : seed length ratio - high numbers indicate a small seed with a long wing; low numbers a large seed with a short seedwing

[edit] References

  • Conifer Specialist Group (1998). Pinus ponderosa. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006.
  • Baumgartner, D. M. & Lotan, J. E. (eds.) (1988). Ponderosa Pine the species and its management. Symposium proceedings. Cooperative Extension, Washington State University.
  • Conkle, M. T. & Critchfield, W. B. (1988). Genetic Variation and Hybridization of Ponderosa Pine. Pp. 27-44 in Baumgartner, D. M. & Lotan, J. E. (eds.).
  • Critchfield, W. B. (1984). Crossability and relationships of Washoe Pine. Madroño 31: 144-170.
  • Farjon, A. (2nd ed., 2005). Pines. Brill, Leiden & Boston. ISBN 90-04-13916-8.
  • Haller, J. R. (1961). Some recent observations on Ponderosa, Jeffrey and Washoe Pines in Northeastern California. Madroño 16: 126-132.
  • Haller, J. R. (1965). Pinus washoensis in Oregon: taxonomic and evolutionary implications. Amer. J. Bot. 52: 646.
  • Haller, J. R. (1965). The role of 2-needle fascicles in the adaptation and evolution of Ponderosa Pine. Brittonia 17: 354-382.
  • Lauria, F. (1991). Taxonomy, systematics, and phylogeny of Pinus subsection Ponderosae Loudon (Pinaceae). Alternative concepts. Linzer Biol. Beitr. 23 (1): 129-202.
  • Lauria, F. (1996). The identity of Pinus ponderosae Douglas ex C.Lawson (Pinaceae). Linzer Biol. Beitr. 28 (2): 99-1052.
  • Lauria, F. (1996). Typification of Pinus benthamiana Hartw. (Pinaceae), a taxon deserving renewed botanical examination. Ann. Naturhist. Mus. Wien 98 (B Suppl.): 427-446.
  • Smith, R. H. (1977). Monoterpenes of Ponderosa Pine xylem resin. USDA Tech. Bull. 1532.
  • Smith, R. H. (1981). Variation in Immature Cone Color of Ponderosa Pine (Pinaceae) inNorthern California and Southern Oregon. Madroño 28: 272-274.
  • Van Haverbeke, D. F. (1986). Genetic Variation in Ponderosa Pine: A 15-Year Test of Provenances in the Great Plains. USDA Forest Service Research Paper RM-265.
  • Wagener, W. W. (1960). A comment on cold susceptibility of Ponderosa and Jeffrey Pines. Madroño 15: 217-219.
  • Gymnosperm Database: Pinus ponderosa
  • USDA Plants Profile: Pinus ponderosa