Nicotiana acuminata
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Nicotiana acuminata var. Multiflora |
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Nicotiana acuminata is a plant type from the genus tobacco ( Nicotiana ). Within the genus it is classified in the section Petunioides .
description
Vegetative characteristics
Nicotiana acuminata is an annual plant that quickly reaches heights of 0.5 to 2 meters. The stem is hairy sticky golden or brownish, the hair consists of inconspicuous, close together, short trichomes . Many long, ascending branches are formed in the lower area. Fewer branches and shorter branches are formed further up.
The plants form only a few indigenous leaves , which also soon wither. The leaf blade reaches lengths of 6 to 12 centimeters, mostly they are ovate to round ovoid in shape. The base is shaped variably, often both halves are unevenly shaped. The leaves are pointed towards the front. Both leaf surfaces are finely haired, the upper side is usually clearly roughened. The leaf stalks are almost as long or shorter than the leaf blade.
The leaves standing on the stems have 10 to 25 centimeters long leaf blades that are ovate to lanceolate or triangular in shape. The leaf stalks usually reach a third to a sixth the length of the leaf blade. The uppermost leaves increasingly become elongated, lanceolate, almost sessile bracts.
Inflorescences and flowers
The inflorescences are pseudo- racemes or elongated, flat panicles , the flowers open at night. The flower stalks are 5 to 10 (rarely 3 to 20) millimeters long, later they lengthen to 10 to 20 (sometimes up to 25) millimeters.
The calyx is 15 to 20 (rarely only 12) millimeters long, cylindrical-bell-shaped and sticky hairy. The blackish-green veins and long, colorless, skinned areas make it appear streaked. The edge of the calyx is covered with unevenly shaped, slender, blunt teeth, the longest of which can be as long as the calyx tube. The crown is white, on the outside a little greenish, oily-metallic and has purple stripes. It becomes 25 to 90 millimeters long excluding the coronary hem. A narrower area at the base is 8 to 35 millimeters long and 2 to 3 millimeters wide, the adjoining crown throat is almost cylindrical, about the same length or 1.5 times longer than the area at the base. The coronary hem measures 10 to 18 millimeters in diameter, is splayed and colored white on the inside. It is weakly lobed, the corolla lobes are entire to slightly curved.
The five stamens have either three different lengths or only a single one is slightly shorter than the rest, they do not protrude beyond the coronet. They all start at the base of the crown throat and are sometimes slightly curved there. In the lower area they are usually finely haired over a length of a few millimeters.
Fruits and seeds
The fruits are broadly egg-shaped capsules with a length of 10 to 15 millimeters. They are surrounded by expanded calyxes. The seeds are angled kidney-shaped or triangular and 0.9 to 1.0 millimeters long. They are gray-brown in color, have a ribbed, reticulated surface and contain a curved embryo .
Distribution and locations
The distribution area of Nicotiana acuminata is in the middle altitudes in Chile and the Argentine Andes , with the exception of the northernmost and southernmost areas. One of the varieties is naturalized in the western United States . The locations have stony, gravelly or sandy soils. The plants can be found on dry slopes, washouts, roadsides and other disturbed locations in full sunlight or partial shade. In Chile the species is found at altitudes between 100 and 3450 meters, in Argentina only up to 1800 meters.
Systematics and number of chromosomes
Within the genus Nicotiana , Nicotiana acuminata is classified in the Petunioides section . All species in the section are annual herbs with a chromosome number of n = 12 and a diploid chromosome set, most species are common in the southwest of the Andes . Nicotiana acuminata is most closely related to Nicotiana attenuata .
The species is divided into three varieties:
- Nicotiana acuminata var. Acuminata
- Nicotiana acuminata var. Multiflora (Philippi) Rich
- Nicotiana acuminata var. Compacta Goodspeed
literature
- Thomas Harper Goodspeed: The Genus Nicotiana: Origins, Relationships and Evolution of its Species in the Light of their Distribution, Morphology and Cytogenics , 1954. Reprinted from AJ Reprints Agency, New Delhi, India, 1982.
proof
- ↑ James J. Clarkson et al .: Phylogenetic relationships in Nicotiana (Solanaceae) inferred from multiple plastid DNA regions . In: Molecular Phylogenetics and Evolution , Volume 33, 2004. pp. 75-90. doi : 10.1016 / j.ympev.2004.05.002
- ↑ Sandra Knapp, Mark W. Chase and James J. Clarkson: Nomenclatural changes and a new sectional classification in Nicotiana (Solanaceae) . In: Taxon , Volume 53, Number 1, February 2004. pp. 73-82.
- ^ TH Goodspeed, H.-M. Wheeler and PC Hutchinson: Nicotiana acuminata, Taxonomic Treatment In: Thomas Harper Goodspeed (Eds.): The Genus Nicotiana: Origins, Relationships and Evolution of its Species in the Light of their Distribution, Morphology and Cytogenics , 1954. Reprinted by AJ Reprints Agency , New Delhi, India, 1982. pp. 421-425.
