Bartsia

Alpine Helmet ( Bartsia alpina)

Bartsia is a plant genus of the family of broomrape family ( Orobanchaceae ). This semi parasite ( hemiparasite ) are predominantly perennial, but also annual herbaceous plants.

German name for the genus are "Bart rail " or " Alps helmet". The latter name corresponds to the trivial name of the species Bartsia alpina, but is quite inappropriate as Gattungsbezeichner because of the approximately 50 species Bartsia this occurs only in Central Europe.

Description

Bartsia - type are mainly perennial, but also annual herbaceous plants.

Ecology

Bartsia species are semi- parasites ( hemiparasite ).

Pollination biology

Within the genus occur three pollination syndromes: bee pollination ( Melittophilie ), bird pollination ( Ornithophilie ) and self-pollination ( autogamy ). During the last two derived groups are limited to certain species, the majority of Bartsia species of bumble bees ( bees of the genus Bombus) is pollinated. Bee pollination is thus evident the underlying pollination syndrome of the genus.

In the Holarctic faces a single Bartsia - type, the Alps helmet, a variety of bumblebee species in the montane regions of the Neotropics, it behaves exactly the opposite comes to relatively few species of bumblebee a variety of Bartsia species. Such conditions generally promote the ecological niche division, which has led in some cases to a caste differentiation within the Bestäuberart: So Bartsia laticrenata is pollinated by long-tongued Bombus funebris the - queens who kleinblütigere Bartsia melampyroides contrast of the kurzrüsseligen workers the same hummelart. Bumblebee -pollinated Bartsia species are mostly diploid, perennial herbaceous plants or subshrubs with loose inflorescences ( inflorescences ) and medium (15-30 mm long ), vorweiblichen ( protogynen ) flowers. Based on morphological criteria, it is also the Afromontane representative whose pollination biology is still poorly studied, assign the melittophilen species.

Bird pollination, however, is only known from South American Bartsia species, where many species of section Laxae and two specialized species of section Diffusae (B. serrata, B. tricolor) are pollinated by hummingbirds. Bird -pollinated Bartsia species are relatively tall-growing herbs or subshrubs with large inflorescences; The flowers are bright red and larger than in related non ornithophilous species.

In striking contrast, there are some niedrigwüchsige Bartsia types of high Andes with dichtblütigen inflorescences and only slightly colored, nearly cleistogamous flowers, which are often more or less hidden among the leaf -like bracts. These species are restricted to habitats above the treeline, where the harsh weather conditions often unfavorable for pollination by animals ( Zoogamie ) are. Self- pollination in these species belonging to the section in the majority Strictae, the only reliable method of reproduction. Therefore, almost all species of this type of distribution are at least facultatively autogamous. Most of the predominantly autogamous species is also tetraploid (see below).

Spread Biology

It develop dry, ovoid to hemispherical, bivalve, vielsamige capsule fruits. The 20 to 200 seeds per fruit are light, dry, almost white and have 6 to 13 wings that are reduced in some species of dry habitats on ridges or ribs.

Because of the winged seeds Bartsia long been classified as wind spread ( anemochor ). This Anemochorie but doubted by Molau (1990 ) based on its own field trials. Instead, he proposes a two -stage propagation mechanism in which the seeds are first released en masse from the ripe capsules in the immediate vicinity of the mother plant. On the ground they absorb water in order to effectively adhere to smooth, wet surfaces (such as the mouths and hooves of grazing animals ) in the second step with the help of her wet wings can ( " adhesive Zoochorie "). In this way, at least a small part of the seed can cover distances up to several kilometers.

Since the seeds are buoyant, even water distribution ( Hydrochorie ) plays a role, such as the occurrence of B. alpina on lakeshores and big rivers far below their actual show alpine and subalpine habitats.

Cytology

The basic chromosome number x = 12 Most Bartsia species are diploid (2n = 24). Tetraploid species ( 2n = 48 ) are known from all Andean sections in the section Strictae tetraploidy is predominant.

Occurrence

The total area of the genus is highly fragmented ( disjoint ), with three main areas of distribution:

• South American Andes ( sections 4-7): neotropisch
• High mountains of tropical East Africa ( section Longiflorae ): Afromontane forests
• Europe and North America ( section Bartsia ): circumpolar - amphiatlantisch

Bartsia trixago ( section Bellardia ) originates probably from the Mediterranean, but has been dragged around the world and is used today in all subtropical and many tropical parts of the world.

So the manifold center is with 45 species in South America. As a center of origin, however, Africa is assumed that the species occuring in the most primitive members of the genus.

Typical elements of the alpine flora of Europe, Africa and South America the Bartsia species usually colonize open, fully sunny locations ( meadows, spring and fens, glades ) in the tree line and above it. The few occurring at lower altitudes species ( Bartsia trixago, some populations of Bartsia alpina) can be found either in fens or in disturbed habitats such as pastures and fields.

System

The genus Bartsia was erected in 1737 by Carl Linnaeus in Hortus Cliffortianus and named in honor of the German physician Johann Bartsch. From its original five species, only two species ( Bartsia alpina and Bartsia trixago ) are conducted in this genre in today's opinion, while " Bartsia viscosa " are assigned to the genus Parentucellia and " Bartsia coccinea " and " Bartsia pallida " of the genus Castilleja.

Bartsia trixago is provided by various authors to the genus Bellardia ( = Bellardia trixago (L. ) All. ).

After Molau (1990 ) The genus contains 49 species in seven sections: