Oryctes nevadensis
| Oryctes nevadensis | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Oryctes | ||||||||||||
| S. Watson | ||||||||||||
| Scientific name of the species | ||||||||||||
| Oryctes nevadensis | ||||||||||||
| S. Watson |
Oryctes nevadensis is a species of plant inthe nightshade family (Solanaceae). It is the only species in the genus Oryctes .
description
Vegetative characteristics
Oryctes nevadensis is a dwarf annual plant with a height of only 5 to 20 cm. It is not very branching, usually three branches - one in the middle and two on the side - are formed. The hairiness makes them appear tomentose, the trichomes on leaves, twigs and the calyx are simple, branched or glandular. In the latter, the trichome stalks are three to five-celled and the heads are one or multi-celled.
The leaf blades of the small, somewhat fleshy leaves are ovate, elongated ovoid or linear, the edge is entire or slightly wavy. They are 10 to 30 mm long and are on 5 to 10 mm long petioles .
Inflorescences and flowers
The stalked flowers are in terminal, racemose inflorescences each with four to five flowers. The stems are shorter than the flowers. The zygomorphic calyx is bell-shaped, five-part and about 2 to 3.5 mm long. The unequal, triangular and elongated parts of the calyx are shorter than the calyx tube. The approximately 6 cm long, yellow-green or yellowish to purple-brown crown is tubular. The five corolla lobes are short, upright, triangular, slightly unequal in length, as long as wide.
The stamens do not usually protrude beyond the crown, only the longest two can be as long or only slightly longer than the crown. The cylindrical or slightly awl-shaped stamens , which attach to the base of the crown with a rectangular structure, are about five times longer than the anthers . These are fixed to the stamens at the base, short, wide and about 0.8 to 0.9 mm long. The theka are slightly different in size and stand free from each other in the lower 1/3 to 1/4.
The ovary is pear-shaped to almost spherical, the nectaries are ring-shaped, the stylus is cylindrical, the stigma is disc-shaped, indented with a central pit.
Fruits and seeds
The fruits are capsules with a diameter of 6 to 7 mm, they are tightly surrounded by an enlarging, somewhat longer, calyx with weak veins. There are around 10 to 15 seeds in each fruit . These are almost circular and strongly pressed in. They have a diameter of 2.2 to 3.5 mm and the surface is honeycomb. The edge is winged except for the hyaline . The embryo is helically curved, the cotyledons are shorter than the rest of the embryo. The endosperm is sparse.
Occurrence and locations
The only species of the genus grows endemically at an altitude of 1,200 to 1,800 m in the mountains of California and western Nevada . They can be found in the deep, loose sand of stable dunes, in valleys and on various slopes, but always dependent on sand dunes or deep sand.
Danger
Reports of occurrences of the species suggest that there are only about 24,000 individual plants of Oryctes nevadensis in Nevada, and there is no trend in development. The “Nevada Natural Heritage Program” included it in the “Sensitive List”, and the species is also included in other conservation programs.
literature
- Armando T. Hunziker: The Genera of Solanaceae . ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001. ISBN 3-904144-77-4 .
Individual evidence
- ↑ a b Nevada Natural Heritage Program: Oryctes navadensis ( Memento of the original from October 1, 2006 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Rare Plant Fact Sheet, Compiled June 25, 2001.
