Robin Ussery & Irina Kim
University of Georgia, Athens
Pines are among the oldest terrestrial plants in the world, first appearing
more than 60,000,000 years ago during the Mesozoic era and emerging as highly successful competitors amongst the world's flora (Everett, 1981).
Pines exhibit the greatest diversity of habitat and distribution of the the needle-type evergreens, being scattered throughout the Northern Hemisphere from the Arctic Circle to Guatemala, the West Indies, North Africa, and Malayan Archipelago (Dirr, 1975). Only one species, P. merkusii
in Sumatra, has crossed the equator (Everett, 1981).
Pines are generally large trees, with only a few
dwarfish or shrubby species. Their flowers can only be called such in the
most primitive sense. Male and female flowers are separate structures:
the female flowers are the structures that will eventually become the familiar
cones containing the seeds, and male flowers release pollen, which is then
captured by the female cones. The pollen may not be released for a number
of years, and even then some species require heat from forest fires, or
other random events in order to open up. Pines are very important to modern-day
industry, including the production of timber, pulp, and paper manufacture.
In addition, turpentine, pine-wood oil, wood tars, and rosin are obtained
from several species. Some species produce leaf oils which are used for
medicines, and many others produce seeds which are used for food, i.e.
"pine nuts" (Dirr, 1975).
The genus Pinus can be distinguished by long needles on very short shoots
in bundles of 2,3, or 5, strobili on long shoots, and the fact that the
shoots and foliage are strongly dimorphic. Other genera in that family
have one or more of the following characteristics: strobili on short shoots,
shoots not or only weakly dimorphic, and foliage that is monomorphic. Although
there are some potential conflicts with certain species and the above mentioned
characteristics, members of Pinus are generally very distinctive
(Farjon, 1990). Listed below is a general key that might prove useful in
distinguishing Pinus from other tree genera:
|P. albicaulis||White Bark Pine|
|P. aristata||Bristle-cone Pine; Hickory Pine|
|P. arizonica||Arizona Yellow Pine|
|P. attenuata||Knob-cone Pine|
|P. ayacahuite||Mexican White Pine|
|P. balfuriana||Foxtail Pine|
|P. banksiana||Jack Pine|
|P. bungeana||Lacebark Pine|
|P. canariensis||Canary Island Pine|
|P. caribaea||Slash Pine; Swamp Pine; Cuban Pine|
|P. cembroides||Mexican Nut Pine; Pinyon|
|P. clausa||Sand Pine|
|P. contorta||Beach Pine; Shore Pine|
|P. coulteri||Big-cone Pine; Coulter Pine|
|P. devoniana||Rough-barked Mexican Pine|
|P. echinata||Shortleaf Pine; Yellow Pine|
|P. edulis||Nut Pine|
|P. elliottii||Slash Pine|
|P. flexilis||Limber Pine; Rocky Mountain Pine|
|P. glabra||Spruce Pine; Cedar Pine|
|P. lambertiana||Sugar Pine|
|P. massoniana||Masson Pine|
|P. merkusii||Merkus Pine|
|P. monophylla||Nut Pine; Pinon|
|P. montezumae||Rough-barked Mexican Pine|
|P. monticola||Western White Pine|
|P. muricata||Bishop Pine|
|P. palustris||Long-leaved Pine; Southern Pine|
|P. patula||Spreading-leaved Pine|
|P. pinaster||Maritime Pine|
|P. pinea||Stone Pine; Umbrella Pine|
|P. ponderosa||Western Yellow Pine; Ponderosa Pine|
|P. pseudostrobus||False Weymouth Pine|
|P. pungens||Table Mountain Pine; Prickly Pine|
|P. radiata||Monterey Pine; Radiate Pine|
|P. resinosa||Red Pine; Norway Pine|
|P. rigida||Pitch Pine|
|P. roxburghii||Long-leaved Indian Pine; Chir Pine|
|P. sabiniana||Digger Pine|
|P. serotina||Pond Pine; Black Pine|
|P. strobus||Eastern White Pine|
|P. sylvestris||Scots Pine|
|P. taeda||Loblolly Pine; Frankincense Pine|
|P. teocote||Twisted-leaved Pine; Aztec Pine|
|P. uncinata||Mountain Pine|
|P. virginiana||Scrub Pine|
Leaves linear or scale-like with resin ducts,
flowers in cones or cone-like, fruit in cones . . . Pinaceae
a. leaves opposite or ternate
a. leaves spirally arranged . . .
b. cones elongate with basally attatched scales,
leaf buds scaly. . .
c. leaves not in fascicles or whorls, borne singularly
c. leaves in fascicles of 2-5 or clustered. .
d. evergreen, leaves in sheathed fascicles of
2-5. . . Pinus
b. plant otherwise
More specifically, to distinguish the species
Pinus echinata and Pinus taeda from the various other pine
species, below is a general key that could be used as a quick reference:
Common names & synonyms
a. leaves 5 to a fascicle
a. leaves 2 or 3 to a fascicle. . .
b. cones unarmed with a spine or prickle, 2 leaves
b. cones armed with a spine or prickle, 2 or 3
leaves per fascicle. . .
c. cones 15-25 cm long, leaves 20-45 cm long
c. cones 3-12 cm long, leaves 2-20 cm long. .
d. spines of cone-scales 5-6 mm long
d. spines of cone-scales 1-3 mm long. . .
e. leaves rigid, 1.5-3 mm broad
e. leaves firm to subrigid, 0.7-1.5 mm broad.
f. old cone 6-12 cm long, leaves 12-25 cm long
. . . P. taeda
f. old cone 4-6 cm long, leaves 4-13 cm long.
g. spine of cone 2-3 mm long, leaves 4-8 cm long
g. spine of cone is minute (1 mm long). leaves
7-13 cm long . . .P. echinata
- Vascular Plants,
Great Smoky Mountains National Park, North Carolina & Tennessee
Onconee National Forest, Georgia
- world-wide distribution north of the equator ( with the exception of the tropical P. merkusii ) to the Arctic Circle
How to encounter
Links to other sites
- Chittenden, Fred J., O.B.E., F.L.S., V.M.H. (ed.). 1951. Dictionary
of Gardening (Vol. III). Clarendon Press. Oxford. 1582-1588.
- Dirr, Michael A. 1975. Manual of Woody Landscape
Plants (4th ed.). Stipes Publishing Co. (ISBN 0-87563-347-1). 605-606.
- Everett, Thomas H. 1981. Encyclopedia of Horticulture
(Vol. 8). Garland Publishing, Inc. (ISBN 0-8240-7238-3). 2647-2653.
- Farjon, Aljos. 1990. Pinaceae. Koeltz Scientific
Books, USA. (ISBN 3-878762-044).
- Fernald, M. L. 1950. Gray's Manual of Botany
(8th ed.). American Book Company, USA.
- Pitt, J. I. et al. 1993. Names in Current Use in the Families Trichocomaceae,
Cladoniaceae, Pinaceae, and Lemnaceae. Koeltz Scientific Books. Konigstein,
- Usher, George. 1974. A Dictionary of Plants Used By Man. Hafner
Press. (ISBN 02-853800-5).