Pinus serotina
Pinus serotina in the United States Botanic Garden
Pinus serotina is an evergreen coniferous tree of the genus pine (Pinus ), usually with 15 to 20 centimeters long, growing in groups of three or four needles and 6 to 10 inches long seed cones. The natural range is located in the southeastern United States. The species is frequently the species Pinus rigida assigned as a subspecies or variety, their species status is, however, generally recognized. It is classified as endangered in the IUCN Red List. The species is exploited economically less and mainly for the production of pulp.
- 5.1 Literature
- 5.2 Notes and references
Description
Appearance
Pinus serotina grows as evergreen, up to 20 meter high tree. The trunk is straight or crooked and often reaches a diameter at breast height of 60 centimeters. The Stammborke is thick and breaks into dark reddish brown, irregularly rectangular, flat, however, scaly plates that are separated by deep cracks. The main branches are horizontal or ascending, they are twisted, shorten with time but little, and form an irregular, thin crown. The needled branches are thick and not very numerous. Young shoots are about an inch thick, at first yellowish orange and often Glauk, later occupied brown and with numerous buds. Frequently Adventitious are rarely also formed on the largest branches of the crown, the trunk.
Buds and needles
The buds are narrowly ovoid to cylindrical and highly resinous. Terminal buds are 15 to 20 millimeters long. Trained as bud scales Lower leaves are reddish brown, pressed, margins and sharply pointed. The needles usually grow to three, rarely four of us, in a basal, initially 20 to 25 millimeters long, shortening to 10 mm needle sheath. Adventitious have three to five needles per cluster of needles. The needles are green, straight, flexible, slightly twisted, usually 15 to 20 centimeters, rarely from 13 and to 21 centimeters long and 1.3 to 1.5 rarely to 2 millimeters thick. You spend two to three years on the tree. The needle edge is finely serrated, pointed the end. On all sides there are needle stomatal lines.
Cones and seeds
The pollen cones grow spirally arranged in groups at the base of young shoots. They are yellowish brown, cylindrical, and 2 to 3 inches long. The seed cones grow singly or in whorls of two to five, sitting or up to 1 cm long stalks. The cones are ovoid closed - conical, symmetrical and usually from 5 6 to 10 inches long. The cones open after two years or triggered by fire later. They are open broadly ovate to almost spherical, with a flattened base and a diameter of 8 centimeters. They remain several years after the delivery of the seeds on the tree. The seed scales are thin woody, oblong, stiff and dull brown with a reddish-brown margins. The apophysis is slightly elevated, transversely keeled, more or less rhombic in outline, light brown or pale reddish brown. The umbo is small, conical, and usually armed with a short, weak sting, sometimes unarmed. The seeds are wrong ellipsoid, slightly flattened, 5-6 mm long, pale mottled brown and dark brown. The seed leaves are 15 to 20 millimeters long.
Chromosome number
The chromosome number is 2n = 24
Distribution, ecology and hazard
The natural range of Pinus serotina is located in the southeastern United States, ranging from New Jersey on the Delaware, Georgia, Maryland, North Carolina, South Carolina and Virginia as far as Alabama and Florida.
The species grows in humid, swampy lowlands on the Atlantic Ocean and the Gulf of Mexico from sea level to an altitude of 200 meters. The climate is mild and humid with an annual annual rainfall 1120-1420 mm and the driest months in the winter. The distribution area is the Hardiness Zone 8 attributed with mean annual minimum temperatures between -12.2 ° and -6.7 ° C (10 ° to 20 ° Fahrenheit ). Pinus serotina often grows together with the rights bald cypress (Taxodium distichum), other pines such as Pinus taeda and Pinus elliottii and deciduous trees such as representatives of the Tupelobäume ( Nyssa ) and Magnolia (Magnolia ), the tulip tree ( Liriodendron tulipifera ) and species of the genus Persea and Holly (Ilex ). The species forms an open canopy beneath which forms a dense growing undergrowth, which is characterized by the sarsaparilla Smilax laurifolia. New exorcise your ability distinguishes them from the similar species Pinus rigida, because it is the Adventitious rather in the crown area instead of the trunk. This is probably an adaptation, since breaking out in the humid environment fire rather in the crown area.
The IUCN Red List is classified Pinus serotina as not at risk ( " Lower Risk / least concern "). It is noted, however, that a reassessment is necessary.
Systematics and history of research
Pinus serotina is a species in the genus of pine (Pinus ), in which it is assigned to the subgenus Pinus, section and sub-section Trifoliae Austral. It was described in 1803 by André Michaux in Flora Boreali - Americana for the first time scientifically. The genus name Pinus was already used by the Romans for several pine species. The specific epithet serotina comes from the Latin and means " late" or " late coming " and refers to the often late, triggered only by fire Open seed cones.
Pinus serotina forms both with Pinus rigida Pinus taeda as well as with natural hybrid, but is usually regarded as a separate species. It is closely related to Pinus rigida, with which it shares the formation of adventitious, but there are a number of differences, but usually only quantitative, justifying the species status. Differences in the length of the needles, and at the time, when open, the seed cones. Also, habitat and ecology overlap only to a limited extent. However, where it overlaps are, as in southern New Jersey and on the Delmarva Peninsula, Delaware and Maryland, there is a continuous transition between the two species. Therefore, the taxon has been described both as a subspecies as well as a variety of Pinus rigida, Pinus rigida synonyms so that the result subsp. serotina ( Michx. ) and Pinus rigida var RTClausen serotina ( Michx. ) Engelm ..
Use
The wood of Pinus serotina is coarse pores and resinous and the trees reach only a small amount, often have crooked trunks, which are divided into long branches in just two -thirds of the full height. The wood is therefore usually further processed into pulp. The slow growth in the nutrient-poor, acidic and marshy surroundings make a useful little interesting. However, the species grows much better in plantations on well-drained, sandy substrates. Attempts to use them for forestry in China ( in the provinces of Jiangsu, Jiangxi, Zhejiang ), South Africa and Zimbabwe, but had less success than with other pine species.