Pinus praetermissa
Pinus praetermissa is an evergreen coniferous tree of the genus pine (Pinus ), usually with five of growing 10 to 16 centimeters long needles and 5 to 6.5 centimeters long seed cones. The natural range is in Mexico. The species is classified as not threatened in the IUCN Red List. There is no known specific use.
- 5.1 Literature
- 5.2 Notes and references
Description
Appearance
Pinus praetermissa grows as evergreen, usually 10 to 15 meters, rarely to 20 m tall tree or shrub. The trunk is twisted or curved and may have branch near the bottom. The diameter at breast height is about 30 inches. The Stammborke is thin and divided into irregular, elongated and reddish brown patches which are separated by shallow furrows. The branches are horizontal, they are long, twisted, forming a broad, irregular, open crown. Young shoots are thin, hairless, reddish brown at first and later gray -brown.
Buds and needles
The vegetative buds are resinous and ovate oblong to cylindrical. Terminal buds are 10 to 15 millimeters long, seitständige buds are ovate - pointed and smaller. Trained as bud scales Lower leaves are light brown, subulate, not reflexed, 7-10 mm long and trockenhäutig. The needles usually grow to five, rarely four of us in a 11 to 14 millimeters long, shortening 7 to 12 mm, consistent, under influence of weather dark-brown to gray needle sheath that falls with the needle bundle. The needles are light green, straight, thin, pliable but not pendulous, from 8 usually 10 to 16 centimeters long and 0.5 to 0.8 millimeters thick. The needle edge is finely serrated, pointed the end. On all sides there are indistinct needle stomatal strips. There are usually formed one or two rare to four thin resin canals. The needles remain two to three years on the tree.
Cones and seeds
The pollen cones are pink to reddish, ovate -oblong to cylindrical, 1 to 1.5 inches long with a diameter of about 5 millimeters. The seed cones usually grow solitary, rarely opposite, near the ends of branches on thin, up to 35 millimeters long, curved stems. Full-grown cones are broad - ovate to almost round, and sometimes wider than long, often opened with a flattened base, usually 5 to 6.5 centimeters, rarely from 4 to 7 inches long and in diameters from 5 usually 6-8 centimeters. Most 50 to 80 to 120 rare seed scales are oblong, straight or bent back, more or less symmetrical, thin woody and stiff. The apophysis is flat to slightly elevated, keeled radially striated to cross, rhombic in outline to pentagonal and shiny light brown to shiny yellowish brown. The umbo is dorsal, it is flat to slightly raised and dull. The seeds are skew- ovate, 5-8 mm long, 3-4 mm wide, dark gray or black spotted. The seed wings are 12-18 mm long, 5-8 mm wide and gray-brown.
Distribution, ecology and hazard
The natural range of Pinus praetermissa is located in Mexico in the states of Durango, Jalisco, Nayarit and Sinaloa. In Mexico, the species has the most restricted distribution area of all pine species of the genus Pinus, Pinus only maximartinezii and Pinus rzedowskii from the subgenus strobus have smaller distribution areas.
Pinus praetermissa grows in dry, open mixed forests of pine and oak trees or in tropical deciduous forests on rocky ground in from 900 to 1,900 meters. The distribution area is the hardiness zone 9 attributed with mean annual minimum temperatures between -6.6 ° and -1.2 ° C (20 ° to 30 ° Fahrenheit ). The annual rainfall ranges from 1000 to 1500 millimeters, November to May, a dry period. The species grows along with Pinus devoniana, lumholtzii Pinus, Pinus pseudostrobus and possibly Pinus oocarpa.
The IUCN Red List is classified as Pinus praetermissa not endangered ( " Lower Risk / least concern "). It is noted, however, that a reassessment is necessary.
System
Pinus praetermissa is a species in the genus of pine (Pinus ), in which it is assigned to the subgenus Pinus, section and sub-section Trifoliae Austral. Representatives of the taxon was until 1990 the species Pinus oocarpa assigned and described in 1990 by Brian Thomas Styles and Rogers McVaugh in the Contributions from the University of Michigan Herbarium as a separate species. The genus name Pinus was already used by the Romans for several pine species. The specific epithet praetermissa comes from the Latin, meaning " see " or " skipped " and refers to the fact that the type for a long time was not recognized as such. A synonym of the species is Pinus oocarpa microphylla var Shaw.
Pinus praetermissa is closely related to Pinus oocarpa, whereby especially the closed resemble cones. Open cones of Pinus oocarpa remain long after delivery of the seed of the tree, while the cones of Pinus praetermissa soon after opening fall. The needles of Pinus praetermissa are shorter and softer and show less stomatal strips and less resin canals.
Use
There is no known specific use, probably the wood is used together with the other pine species. A horticultural use is not known.