Odontites hollianus
| Odontites hollianus | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Odontites hollianus |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Odontites hollianus | ||||||||||||
| ( Lowe ) Benth. |
The Madeira eyebright ( Odontites hollianus ) is a semi-parasitic plant species from the genus of the tooth rust ( Odontites ). It is only on Madeira occurring endemic .
description
Odontites hollianus is an annual herbaceous plant that grows 20 to 40 cm (rarely 15 to 55 cm) high . Their stem is up to 3 mm thick at the base. The entire plant is densely covered with protruding, bristly trichomes , but the stem glands are missing. The vegetative part of the stem axis consists of ten to 25 nodes , of which the upper four to ten form side branches. These are up to 15 cm long and are at an angle of 30 to 50 °.
The leaves are ovate-lanceolate, reach a length of 25 to 40 mm and a width of 5 to 13 mm. The leaf margin is roughly serrated with ten to 14 teeth, about 2 mm long. Most of the foliage leaves fall off shortly after flowering.
The inflorescences are only indistinctly separated from the vegetative part, an inhibition zone is often missing or consists of a maximum of three nodes. The inflorescences consist of only five to ten flowers , which are already loosely arranged at flowering time. The length of the inflorescence is initially 5 to 10 cm, when the fruit ripens it extends to 24 cm. The bracts are leaf-like, lanceolate and usually clearly toothed. Only rarely is the edge of the bracts entire. The size of the middle bracts is 10 to 15 (rarely up to 26) × 2 to 4 (rarely up to 8) mm. The blooming sequence of the flowers of an inflorescence is from bottom to top.
The flowers are protogynous (female) and reach a length of (rarely only 10) 12 to 15 mm. The calyx has a length of 6.2 to 9 mm at flowering time, on the fruit it extends up to 16 mm. The individual sepals stand free from each other for about half their length and are densely hairy with bristles. Stalk glands are also absent here, the short glands with two to four-celled heads are up to 72 µm long. The calyx lobes are narrow triangular. The crown is colored yellow and hairy with 0.1 to 0.2 mm long trichomes, also found in the upper part of the corolla tube is about 0.1 mm long short glands. The corolla tube has a length of 7 to 10 mm, the edged helmet is 4.5 to 5 mm about as long as the lower lip. This is split into three lobes over half the length. The middle tip is spatulate, widened, clearly delineated and about as long as wide. The side tips are only slightly shorter than the middle, they are almost semicircular and also have a border and are wider than long.
The four stamens are partially enclosed in the helmet. The top pair is 2.5 to 3.5 mm long and the bottom pair is 4 to 5 mm long. The stamens are covered with papillae . The yellow anthers are at an angle of about 90 ° to the stamens. The counters jump up over their entire length, narrowing into a granny point. On the connective tissue there are 0.5 mm long tubular hairs, on the upper, blunt end spiral hairs, otherwise the anthers are hairless. The pollen grains have an average size of 31.1 × 33.4 µm. The ovary is zweifächrig and total constitutes about 36 to 40 ovules from. The stylus has a length of up to 10 mm.
The fruits are inverted egg-shaped capsules that reach a length of 6.2 to 12 mm and a width of 3 to 5 mm. The seeds are 1.1 to 1.5 mm long and 0.5 to 0.75 mm wide.
The number of chromosomes is 2n = 24.
Occurrence
The species is endemic to Madeira , where it grows in the central mountains at Pico do Cedro and Pico do Arieiro . The locations are at altitudes between 1100 and 1750 m on rocky steep slopes in the subtropical cloud forest belt, in damp, often springy places.
literature
- Markus Bolliger: Monograph of the genus Odontites (Scrophulariaceae) and the related genera Macrosyringion, Odontitella, Bornmuellerantha and Bartsiella . In: Willdenowia: Annals of the Botanic Garden and Botanical Museum Berlin-Dahlem , Volume 26, 1996. pp. 37-168. (Online: Part 1 (PDF; 2.4 MB), Part 2 (PDF; 1.2 MB), Part 3 (PDF; 1.2 MB), Part 4 ; PDF; 2.1 MB)
Individual evidence
- ↑ Odontites hollianus at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
