Phacelia
Tansy Phazelie ( Phacelia tanacetifolia )
The genus Phacelia belongs to the subfamily of leaf water plants ( Hydrophylloideae ) in the family of Boraginaceae ( Boraginaceae ). Colloquially also names such as honey bees, bee friend, Tufts Beautiful or flower tufts are common. The genus name is derived from the Greek for phakelos tufts from.
Description
The genus Phacelia include one-, two - or perennial species. The herbaceous plants are usually hairy. The alternate and spirally arranged leaves are simple or compound. Stipules absent. The terminal, zymösen inflorescences are rolled on one side and often spiral. The hermaphroditic, flowers are radial symmetry fünfzählig. The five blue-violet, light blue to white petals are bell-like to wheel-shaped together. It's just a circle with five free, fertile stamens present. Usually, the dust bags are hairy. Two carpels are fused into a superior ovaries. It's just a pen available. Pollination is by Hymenoptera (Hymenoptera ) ( entomophily ). Are formed zweifächerige, hairy capsule fruits.
Occurrence
Original home of the genus Phacelia is mainly western North America, the eastern United States and South America, so only the New World. Naturalises comes Phacelia before on roads and roadsides, in fields and dumps. Although the species of the genus are undemanding and drought tolerated but not hardy. Therefore, they can not prevail over a large area in central Europe as a neophyte.
Use
In agriculture the most cultivated varieties of tansy Phazelie ( Phacelia tanacetifolia ).
Use as a beekeeper plant
Phacelia is often sown in Central Europe as bee pasture. It is considered highly productive bee costume plant, whose costume the value of rape or buckwheat corresponds roughly. Each flower produces nectar within 24 hours with a total sugar content of between 0.7 and one milligram. Yields of 500 kg of honey per hectare and flowering season are quite possible.
Use as a soil conditioner
Phacelia is very suitable as a green manure plant. With its dense root system it uses the nutrients in the soil good and passes it via rotting easily succeed fruit. She leaves behind a dense root mass, gare crumb. The delicate leaves lead to a very good soil shading and effective weed suppression. The high amounts of organic material remaining in the soil, maintain or increase the humus content and thus the productivity of the soils. Thus, the soil structure is improved and the yield security takes long term on lighter soils.
Since the stocks in general during the winter freeze and collapse at temperatures below minus 5 ° C, erosion-prone succeeding crops such as sugar beets without break can be sown in the plant residues into mulch or direct seeding.
Resistance to pests, inhibition of pests
The Phacelia is often grown as a cover crop and green manure, because it is the only crop in the subfamily Hydrophylloideae. Thus, there are no problems in the crop rotation, as in related taxa is often the case. In contrast, the occurrence is at kreuzblütigen crops such as oilseed rape, cabbage, radish family- specific diseases such as clubroot favored if the rotation is not observed. In crop rotation with sugar beet cultivation of phacelia is advantageous because it has an inhibitory effect on nematodes ( Rübenälchen ).
Promotion of harmful pathogens
On the other hand, by the cultivation of phacelia as intercrop the causative agent of scurf disease ( Rhizoctonia solani) of maize, beet and potato crops increasingly occur.
Use in viticulture
For intercropping in vineyards about 10 to 12 kg of seed per hectare are sown in the spring. Since it has a very high mass power and a so-called N- Catcher is, it is preferably used in Erstbegrünungen.
Use as feed
Harvested before flowering Phacelia can, such as the sows, also be used as easily digestible feed. In addition to the fresh feed may also be preserved by ensiling.
Importance in genetics
The example of the also occurring in North America Phacelia magellanica group could be demonstrated that reproductive barriers between species in the plant kingdom work far less well than in the animal kingdom, or in other words, that plant genomes can be very flexible.
To include the P. magellanica group types with several ploidy levels, that is, there are respectively breeds that are diploid, tetraploid and hexaploid, and do not cross each other or just bad. The tetraploids of various types, however, intersect with each other relatively easily. The gene exchange between the " tetraploids different species " is therefore lighter than between the Ploidierassen of each the same kind
System
There are 150 to 200 species of Phacelia (selection):
- Phacelia argentea A. Nelson & JF Macbr. It comes only in Oregon and California before
- Phacelia calthifolia fire
- Bell Phazelie or Desert Blue Bell ( Phacelia campanularia A. Gray ): You only comes in California
- Phacelia fremontii Torr.
- Large-flowered Phazelie ( Phacelia grandiflora A. Gray )
- Phacelia magellanica ( Lam.) Coville
- Small Phazelie ( Phacelia minor ( Harv. ) Thell ex Zimm. . ): It occurs only in California and Mexico
- Parry - Phazelie ( Phacelia parryi Torr. ): You only comes in California and Mexico before
- Phacelia rotundifolia Torr. ex S. Watson
- Phacelia secunda JF Gmel.
- Silk Hairy Phazelie ( Phacelia sericea ( Graham) A. Gray ): It occurs only in Canada and the USA
- Tansy Phazelie ( Phacelia tanacetifolia Benth. ): The home is California, Nevada, Arizona and Mexico, but is the type introduced in Europe, Australia and New Zealand before
- Sticky Phazelie ( Phacelia viscida ( Benth. ) Torr. ): The home is California and Mexico.