Pinus squamata
Pinus squamata is a medium sized, evergreen coniferous tree of the genus pine (Pinus ) with four or five of us growing, 9-17 cm long needles. The seed cones reach a length of usually 8 to 10 centimeters. The Stammborke dissolves in irregular scales. The natural range is in a very small area in China and there are only about 36 copies, of which about 20 fully grown. It is thus probably the rarest pine species and one of the rarest conifers at all. The species is therefore classified as critically endangered in the IUCN Red List.
- 5.1 Literature
- 5.2 Notes and references
Description
Appearance
Pinus squamata grows as evergreen, up to 20 meter high tree. The stem is erect and reaches a diameter at breast height of up to 60 centimeters, but there are no old trees known. The Stammborke is smooth, hard and peels off in irregular, thin flakes, exposing the bright, yellowish spots, which later turn from gray-green to various shades of brown, forming a multicolored pattern on the trunk. The main branches grow in Scheinwirteln, spread or ascending, forming a conical or round, open crown. Benadelte branches are thin, smooth, at first pale reddish brown and then gray-brown, densely hairy yellow-brown or gray-brown or glabrous.
Buds and needles
The vegetative buds are ovate, up to 10 millimeters long and resinous. The Lower leaves are reddish brown, imbricate and arranged triangular- lanceolate. The needles grow to four or five in a frail, basal needle sheath. They are bright green, rigid or flexible, straddling, 9-17 inches long, with a broad - triangular cross section and a diameter of about 0.8 to 1.0 millimeters. The needle edge is finely serrated, pointed the end. On all sides there are needle stomatal lines. Are formed near the surface of a single trunk group and three to five large resin canals.
Cones and seeds
The pollen cones grow spirally arranged in elongated groups on young shoots in the axils of broad -leaves. They are ovate - cylindrical, and 10 to 15 millimeters long.
The seed cones grow individually, standing upright or horizontally on a 1.5 to 2.0 cm long stem. They are at first green, and later variably brown, ovoid - conical closed, opened broadly ovate, sometimes from 7 usually 8 to 10 inches long, with a diameter of 5-6 centimeters. They fall when ripe from the tree. The 100 to 120 seed scales are oblong - elliptic, about 2.7 inches long and 1.8 inches wide, woody and stiff. The apophysis is thickened, broadly rhombic in outline and transversely keeled. The triangular umbo is dorsal, it is flat or more or less absorbed and has no sting.
The seeds are flattened oblong or obovate, slightly, 8 to 10 millimeters long, about 5 mm wide and black striped. The seed wing is 15 millimeters long, structured and also shows black stripes.
Pollination is in April and May, the seeds ripen in September and October, the then two year old stud.
Distribution, ecology and hazard
The natural range of Pinus squamata is in the circle Qiaojia in the northeastern Chinese province of Yunnan, where the species was found in only one place.
It is an extremely rare species that grows in almost 2200 meters above sea level on a mountain slope with open, disturbed by humans woodland and grassland with bushes. They can be found along with Pinus yunnanensis and various deciduous trees. The distribution area is the hardiness zone 9 attributed with mean annual minimum temperatures -6.6 to -1.2 ° Celsius.
In the IUCN Red List Pinus squamata is due to the very limited distribution area and the very small population of only 36 copies, of which 18 to 20 full-grown, as critically endangered ( " Critically Endangered " ) classified. Another census comes out of a total of only 29 copies, of which only carry 18 pins. The distribution area is located on a partially deforested northwest slope and is surrounded by feuergefährdetem grass and scrub. An additional danger arises yunnanensis by crossing with Pinus. In the harsh winter of 2008, three of the specimens died off due to the heavy snowfall. However, the area is now a nature reserve and the trees are strictly protected. With the support of local foresters and farmers of several young trees have been bred to be planted in the distribution area later (in 2010 ).
Systematics and history of research
Pinus squamata is a species of the genus pine (Pinus ), in which it is the subgenus strobus, Section Quinquefoliae and associated with two other species of the section Gerardianae. The species was only in 1991 by Pangzhao J.Q. discovered, studied by Li Xingwen in 1991 and first described by him in 1992 in the Acta Botanica Yunnanica. The genus name Pinus was already used by the Romans for several pine species. The specific epithet squamata comes from the Latin and means " scaly ". It refers to the scaly bark of older trees. Synonyms of species are not known.
The scaly bark, the needle shape and structure of the seed cones show the relationship to Pinus and Pinus bungeana gerardiana, the other two types of sub-section Gerardianae. It differs from them by the darker bark, the longer needles to the fourth or fifth growing in the needle sheaths, and the large, functional seed wings. These properties are usually found Strobus the representatives of the sub-section.
Use
The species is not used commercially. You will be able to find later in botanical gardens, initially only in China.