Arnica

Arnica (Arnica montana)

Arnica (Arnica ) is a genus of flowering plants in the sunflower family ( Asteraceae). They are predominantly located in the cooler regions of North America. Only two species occur in Eurasia. Due to its climatic requirements do not count the species of the genus Arnica (Arnica ) of the most common garden plants.

Description

All Arnica species are perennial herbaceous plant, reaching heights of growth between 5 and 100 cm. They form long, thin rhizomes and there are underground stem parts available, which become woody and are relatively short and thick.

The lower leaves are often in rosettes, whereas the upper leaves often sit in one to ten pairs of constantly on the stem. In some species the leaves are stalked, while others do not. The leaf forms within the genus are highly variable, but they are often hairy.

The flower heads are individually or several together in total inflorescences. The bloom conditions are so-called Pseudoanthien; seen flowers are ecologically and flowers are composed of many individual flowers. The bract envelope, the involucre is bell - gyro or hemispherical, they reached a diameter 6-20 mm. The involucre is formed from 5 to 23 tough bracts, which, more often two rows are in a. The inflorescence bottom is convex, can be hairy or smooth, depending on the type, but does not chaff leaves. In the basket- shaped inflorescences are often tongue and tubular flowers. The 5 to 22 yellow to orange ray florets, ray florets also called because they are located at the edge, are fertile, containing stamps and are rarely absent. In the center of the flower head can be found between 10 and 120 tubular flowers, also called disc florets, which are hermaphrodite and fertile. The corolla tube is yellow, rare cream color, and usually shorter than the funnel-shaped necks. The anthers are yellow, purple with Arnica Arnica lessingii and unalaschcensis.

The gray or brown to black achenes possess glands or formed smooth. The pappus consists of 10 to 50 straw-like, white or yellow- brown finely bearded more or less feathery bristles. With Arnica dealbata but these are missing altogether.

The basic chromosome number is x = 19

Dissemination

The genus Arnica is Circumboreal widespread in North America and Eurasia. She prefers montane habitats and reaches its highest diversity in western North America. In Europe there are only two species ( Arnica montana and Arnica alpina). Some species are common and widespread, while other species are endemic and occur only in small ecosystems.

System

The 30 species of the genus Arnica (Arnica ) are:

  • Arnica (Arnica montana L.)
  • Arnica acaulis (Walter ) Britton, Sterns & Poggenb.
  • Arnica alpina (syn.: A. angustifolia subsp alpina. )
  • Arnica amplexicaulis Nutt. ( Syn: . A. lanceolata subsp amplexicaulis ( Nutt. ) Gruezo )
  • Arnica angustifolia Vahl: A. angustifolia subsp. alpina (L. ) I. K. Ferguson
  • A. angustifolia subsp. tomentosa
  • A. chamissonis subsp. foliosa ( Nutt. ) Maguire
  • A. griscomii subsp. frigida ( C. A. Mey. ex Ilyin ) S. J. Wolf (syn.: A. frigida C. A. Mey ex Ilyin. )
  • A. griscomii subsp. griscomii
  • A. lanceolata subsp. amplexicaulis (also known as type A. amplexicaulis Nutt. )
  • A. lanceolata subsp. lanceolata
  • A. lessingii subsp. lessingii
  • A. lessingii subsp. norbergii Hultén & Maguire
  • A. lonchophylla subsp. arnoglossa (Greene) Maguire
  • A. lonchophylla subsp. lonchophylla

Swell

  • Steven J. Wolf: Arnica in the Flora of North America, Volume 21, page 366: Online. (Section Description, distribution and systematics)
Asteroideae Perennial plant Stamen Pappus (flower structure)
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