Pinus echinata
Pinus echinata
Pinus echinata is an evergreen coniferous tree of the genus pine (Pinus ), usually with 6 to 11 inches long, arranged mostly in pairs or groups of three needles and 4-7 cm long seed cones. The natural range is located in the southeastern United States. The species is not endangered and economically important wood supplier is, however, hardly used horticulturally.
- 6.1 Literature
- 6.2 Notes and references
Description
Appearance
Pinus echinata grows as evergreen, 35 to 40 meters tall with a diameter at breast height of up to 160 centimeters. The highest known tree was measured in 1980 with a height of 42 meters and a trunk diameter of 1.1 meters. The Stammborke is dark brown, slightly resinous and breaks into irregular rectangular plates. You crown is oval to dome-shaped. The branches are horizontal and are thin and short especially in trees in forests. Needle -bearing branches are thin and more or less continuous. Young shoots are reddish brown, often bluish overflow and stain later red-brown to gray. They are smooth and rough after the loss of needles by permanent pulvini. There are a formed resin to four channels.
Buds and needles
The buds are ovate to ovate - cylindrical, 5-10 mm long and very resinous. The needles grow in pairs or threes in a 10 to 15 mm long needle sheath and stay three to five years on the tree. They are yellowish green, gray-green or dark green, flexible, straight or slightly curved, rarely from 5 usually 6 to 11 and sometimes up to 12 inches long and about 1 mm wide. The needle edge is finely serrated, the end of short spiky. On all sides there are needle narrow stomatal lines.
Cones and seeds
The pollen cones grow spirally arranged in small groups. They are cylindrical, 15-20 mm long, pale green to yellow and purple color is light brown later. The seed cones grow singly or in whorls of two to four. They are short-stalked or nearly sessile, 4-7 cm long, ovate to ovate - closed narrow elongated and opened broadly ovate to ovate -oblong with a flattened base. The 75 to 100 rare and 120, paddle-shaped seed scales are brown and woody thin, inelastic, green and equally truncated at maturity. The apophysis is slightly raised and sharply keeled transversely. The umbo is armed with a strong, short sting. The seeds are ellipsoid, 6-7 mm long, mottled gray and black, with a similarly colored, 12 to 15 millimeters long seed wings.
Chromosome number
The chromosome number is 2n = pines as with all 24
Branch with needles and young seed cones
Seed cones
Development
Pinus echinata usually forms only after about 20 years, seeds, although even five years copies of both male and female cones were observed. Larger quantities of seeds are produced only by trees with trunk diameters of at least 30 centimeters. The seed delivery begins in late October or early November, wherein each pin 25 to 38 seeds formed. 70 percent of the seeds are released in the first month, 90 percent after two months. The seedlings germinate epigeal, after the seeds were able to overwinter on the ground. There is evidence that some of the seeds begins after the second winter to none, but there is no confirmation for this. Young plants can form a taproot in their infancy, but only lateral roots due to soil conditions usually formed, which then run just below the surface. Young trees have an annual height growth of 30 to 90 centimeters.
Distribution, ecology and hazard
The natural range of Pinus echinata is located in the east and southeast of the United States and spans 22 states from New York and Illinois to the east of Texas and Florida. Outside the natural range it is used for forestry in China. The species grows in its natural habitat in the lowlands at altitudes of 150 meters up to the foothills of the Appalachian Mountains in about 600 meters. However, it is missing in the valley and estuary of the Mississippi River and along a narrow or partly wide strip along the Gulf of Mexico and the Atlantic Ocean and in most of Florida. The northern border of the distribution area is determined by a mean annual temperature of 10 ° Celsius, the southern boundary by a rainfall of about 1000 mm, which is more or less evenly distributed throughout the year. It grows on a variety of different soil types, but usually have a certain amount of water storage capacity, sandy-loamy or silty - clayey texture and good drainage. Pinus echinata sometimes forms pure stands, but is usually accompanied by broad-leaved trees such as oaks (Quercus ). In areas with only a thin soil covering the deciduous trees and the nature of missing grows along with other conifers. They are also found along with Pinus taeda, which has a similar distribution area, but usually occurs on wetter soils. The distribution area is the Hardiness Zone 8 associated with mean annual minimum temperatures of -12.2 ° to -6.7 ° C (10 ° to 20 ° Fahrenheit ).
The IUCN Red List is classified Pinus echinata as not at risk ( " Lower Risk / least concern "). It is noted, however, that a reassessment is necessary.
Systematics and history of research
Pinus echinata is a species of the genus pine (Pinus ), in which it is assigned to the subgenus Pinus, section and sub-section Trifoliae Austral. It was described in 1768 by Philip Miller for the first time scientifically. The genus name Pinus was already used by the Romans for several pine species. The specific epithet echinata comes from the Latin, refers to the hedgehog and means as much as " prickly ". It is unclear, however, has what parts of the plant Philip Miller meant. Synonyms of species are Pinus lutea Lodd. ex Gordon, Pinus mitis Michx. , Pinus royleana Jameson ex Lindl., Pinus squarrosa Walter, Pinus taeda var echinata (Mill.) Castigl. , Pinus taeda variabilis var Aiton, Pinus variabilis ( Aiton ) Lamb. and Pinus virginiana var echinata (Mill.) Du Roi.
The species forms natural hybrids with Pinus taeda and Pinus rigida. Crossing experiments with Pinus elliottii, Pinus pungens and Pinus palustris were successful.
Use
Pinus echinata is in the southeastern United States, both from natural stocks as well as from forestry plantations is an important supplier of timber. The wood has a high quality, an orange to yellowish brown heartwood and creamy- yellow sapwood. It is used for making railway sleepers, used as a timber for panels, furniture, plywood and pulp for the paper industry. The wood from forestry plantations is usually used for making paper.
The trees are also planted as a demarcation and protection of residential areas from highways. Otherwise, the type hardly horticultural importance.