Streptosolen jamesonii
Streptosolen jamesonii | ||||||||||||
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![]() Streptosolen jamesonii |
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Systematics | ||||||||||||
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Scientific name of the genus | ||||||||||||
Streptosoles | ||||||||||||
Miers | ||||||||||||
Scientific name of the species | ||||||||||||
Streptosolen jamesonii | ||||||||||||
( Benth. ) Miers |
Streptosolen jamesonii is a species of plant inthe nightshade family (Solanaceae). It is the only species in the genus Streptosolen .
description
Vegetative characteristics
Streptosolen jamesonii are evergreen, scaly hairy, 1.5 to 2 (rarely up to 2.2) m high shrubs that are densely branched. The dense hair consists of glandular trichomes , the stem is single-row and the head consists of one to four cells that are parallel to the stem. Stone cells are formed in the epidermis and the bark of the trunk , the endodermis contains Casparian stripes .
The leaf blades of the leaves are ovate, stemmed, almost leathery and somewhat wrinkled and rough. The bottom is marked clearly leaf veins , on top of missing the stomata .
Inflorescences and flowers
The flowers are in almost cymes with cymes on 5 to 16 mm long pedicels. The tubular calyx is zygomorphic , criss-crossed with reticulate nerves and 8 to 10 mm long. The four or five calyx teeth are unequal in length and shorter than the calyx tube. The golden yellow or golden red, funnel-shaped crown is zygomorphic and 22 to 30 mm long. The helically twisted corolla tube is not bulbous, the coronet is slightly sloping, rather narrow, the diameter is up to 18 mm. The five corolla lobes are broad and very short, pointed or elongated.
The four stamens have hairy stamens . The upper, laterally located pair is attached between 2/3 and 3/4 of the corolla tube, has shorter stamens about 3 mm long and smaller anthers , in which a theca is usually receded or small or does not exist at all. The other pair has stamens up to 12 mm long, which are attached near the lower 1/4 of the crown, the anthers are significantly larger with 2.5 × 1.8 mm. The pollen are spherical, flattened to spherical, about 33.5 × 36 µm in size and have (rarely only five) seven to eight comparatively large apertures. The pollen grain wall ( exine ) is streaky and wrinkled. The nectaries are ring-shaped and thick.
Fruits and seeds
The fruits are spherical or egg-shaped capsules that are about 5 mm long and contain 60 to 80 seeds . These are 0.6 to 0.9 mm long, cubically elongated, the surface is structured like a network.
Other features
In four investigations carried out, both and were determined as the base chromosome number . The plant contains nicotine , nornicotine and anabasine .
Occurrence
The only species of the genus Streptosolen grows in Ecuador , Peru and probably also in southern Colombia at an altitude of 1,200 to 2,500 m. Occasionally it is grown in gardens as an ornamental plant because of its striking flowers.
literature
- Armando T. Hunziker: The Genera of Solanaceae . ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001. ISBN 3-904144-77-4 .