Solanum herculeum
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Solanum herculeum (Syn .: Triguera osbeckii ) is a species of the nightshade genus ( Solanum ) inthe nightshade family (Solanaceae). The species occurs in the Mediterranean area.
description
Vegetative characteristics
Solanum herculeum is an herbaceous plant up to 0.5 m high . Their stems are green, fleshy, and hollow on the inside. They are sparsely haired with simple, single-row trichomes 2 to 3 mm long that can stand upright or slightly lying flat. The sympodial units each have two leaves that are not in pairs. The leaves are sessile, simple, elliptical to rhombic, 1.5 to 5 cm long and 1 to 4 cm wide. The higher the leaves are on the plant, the smaller they become. The top is hairless or sparsely hairy along the midrib with simple single-row trichomes. The underside is sparsely hairy along the midrib and along the usually five pairs of lateral leaf veins. When drying, the underside becomes slightly reddish. The base of the leaves is heart-shaped and slightly encompassing the stem, towards the front they are blunt-tipped or cut off. The leaf margin is roughly serrated, the teeth can reach up to 1/3 of the width to the midrib. In addition, the leaf margin is covered with simple, single-row trichomes up to 3 mm long. Sometimes short petioles are formed, but they are shorter than 1 mm.
Inflorescences and flowers
The inflorescences arise from the internodes, just below the leaves. They are 0.2 to 0.4 cm long, are simple and consist of two to three flowers . The inflorescence axis is sparsely haired with 2 to 4 mm long, simple and single-row trichomes. The flower stalks are about 2 mm apart, the base is surrounded by a 2 mm long coat that is wrinkled in dry plants. The buds are elliptical, the not yet opened crown is already clearly protruding from the calyx . The flower stalks are 1.4 to 2 cm long and 1 mm in diameter at the time of flowering. They are slender, upright to slightly nodding and sparse to dense with simple, single-row trichomes up to 2 mm long.
The calyx has an open cup-shaped calyx tube with a length of 1 to 2 mm (rarely only 0.5 mm). The calyx tube is covered with 8 to 10 mm long, elliptical calyx lobes, which are pointed towards the front and are densely haired with 1 to 2 mm long, simple, single-row trichomes. The crown measures 2 to 4 mm in diameter, is bell-shaped and dark purple to greenish purple with a bright yellow center. The corolla lobes are only about 1 mm long, curved and very weak. Along the edges of the corolla lobes and at the tips they are densely papillae , the outside is hairy along the main veins with simple, single-row trichomes up to about 1 mm long.
The anthers are of different shapes. There are three short anthers with a length of 3 to 5 mm and a width of about 1 mm, and two longer anthers with a length of 4 to 7 mm and a width of 1 mm. They open through pores at the tips, which later lengthen into slits. At the tips of the anthers there is a weak, horn-shaped appendix with a length of 0.5 mm. The stamens are only exposed for a length of less than 1 mm, the remaining part has grown together to form an approximately 1 mm long stamen tube. The ovary is conical and hairless. It carries a 6 to 8 mm long, hairless stylus that is curved upwards at the end. The scar is finely headed, papilose and often bright green.
Fruits and seeds
The fruits are spherical berries with a diameter of 0.9 to 1.2 mm. They are pale greenish to yellow when ripe and have a very thin pericarp , which becomes paper-like and brittle. The flower stalks are about 1.5 to 2 cm long on the fruit and measure 1 mm in diameter. The calyx is permanent and enlarged on the fruit. The seeds are about 7 × 7 mm in size, ovoid and plump. They are pale straw-colored, the seed surface is very granular and consists of honeycomb-shaped cells with straight walls.
Distribution and locations
The species grows in southern Spain and along the Mediterranean coast of northern Africa along the Strait of Gibraltar . It is mostly found on open, damp areas, often along fences at altitudes between 0 and 100 m.
Systematics and botanical history
Solanum herculeum is classified within the nightshade ( Solanum ) in the Normania clade comprising only three species. The species of the clade were listed as two separate genera for a long time, Solanum trisectum and Solanum nava formed as Normania triphylla and Normania nava the genus Normania and Solanum herculeum the genus Triguera (as Triguera osbeckii ).
The species was first described by Carl von Linné as Verbascum osbeckii in 1753 and thus assigned to a genus that was later assigned to the figwort family (Scrophulariaceae). In 1870 the species was described by Heinrich Moritz Willkomm in the genus Triguera established by Antonio José Cavanilles in 1786 . According to the understanding of the time, this contained the Triguera ambrosiaca described by Cavanilles and the Triguera baccata described by Johann Friedrich Gmelin in 1791 . The status of another species Triguera inodora described by Cavanilles is uncertain as no type specimen is known.
In most of the works, two or three species were distinguished within the genus, until 1973 by Hansen and Hansen the genus was summarized as a monotype. According to the rules of the ICBN, priority was given to the oldest epithet osbeckii . By classifying the genera Normania and Triguera in the genus of nightshade, the preferred name of the species would be Solanum osbeckii , but this was already described by Michel Félix Dunal for a different species in 1852 , which is why Lynn Bohs chose the name Solanum herculeum in 2001 . The name is derived from "Herculeum Fretum", the classic name of the Strait of Gibraltar .
proof
Main sources
- Sandra Knapp: Solanum herculeum . In: Solanaceae Source ( online ), July 2006, accessed February 27, 2011.
Individual evidence
- ↑ a b Lynn Bohs and Richard G. Olmstead: A reassessment of Normania and Triguera (Solanaceae) . In: Plant Systematics and Evolution , Volume 228, 2001. pp. 33-48. doi : 10.1007 / s006060170035