Browallia
Browallia is a genus of flowering plants of the nightshade family (Solanaceae ). The six species come from North to South America before. The species was named in honor of Johan Browall.
Description
Vegetative characteristics
Browallia are erect, annual plants, the plant height between 8 and 60 cm or reach up to 1 m (in rare cases, 1.5 m). You can be glabrous or pubescent hairy to tacky finish - pubescent. The coat consists of simple, multicellular and uniseriate glandular trichomes as well. Glandular trichomes can have a two - or multi-celled stalk, have a unicellular or multicellular head and are always uniseriate. The branch may be weak or strong. In the endodermis Casparian strip not occur.
The leaves are membranous, their shape is cordate - ovate, ovate - oblong, rhombic or linear - oblong. They are up to 6 cm ( rarely to 9 cm) long, are almost blunted or pointed, sessile or stand at 2 to 30 mm long petioles. The mesophyll ( ground tissue of the leaves ) is dorsiventrally glands, stomata are found on both leaf surfaces.
Inflorescences and flowers
Most small flowers appear singly or in racemose inflorescences. The flower stalks are 2 to 40 mm long and a little further growing after flowering. The cup is radial symmetry, 4 to 20 mm long and tubular and bell-shaped. He is a four - or fünfgezähnt or - lobed, the teeth or lobes are usually shorter or about the same length as the calyx tube. The corolla tube is (rarely 1.5 ) two to four times as long as the calyx, 1-20 mm wide and 10-52 mm long. The crown is zygomorphic, salverform and occasionally slightly bilobed. It is 63 to 73 mm long, purple is blue, violet, purple, yellow or cream-colored. The coronary band is 6-52 mm wide and divided into five unequal size Corolla lobe, which may be nearly circular, ovoid or elongated.
There are four stamens formed a fifth is reduced to a bump or missing entirely. You put on in the upper half of the crown and are bowed down along the front Kronlappen. The anthers of the two upper stamens consist almost only of a counter, the second is rejected or is non-existent. The stamens of the two stamens are bent, flattened and occupied glabrous or with long, sometimes branched trichomes. The stamens of the lower two stamens are usually somewhat longer ( but occasionally slightly shorter ) than that of the upper stamen pair, they are turning round and narrow, the anthers are larger with 1 mm in length and consist of two fertile counters that are free in the lower half one another are. The pollen grains are medium in size with 28 to 40 microns in diameter. The ovary is occupied glabrous or at least in the lower half tightly with stiff trichomes. Nectaries are arranged thick and circular, but may be re-formed or missing.
Fruit and seeds
The fruits are upstanding capsules are spherical, elongated, tapered, or vice versa. They are 4.5 to 6 mm long and contain ten to 45 seeds. These are cubic shaped, angled and (0.5 ) 1 ( 1.5 ) mm long. The seed coat is reticulate - pitted or tuberculate.
Other features
The base chromosome number is depending on the type x = 10 or x = 11
System
Both in the mainly morphologically justified classification of Solanaceae by Armando Hunziker and in the molecular biologically based classification by Richard Olmstead, the genus is classified together with the genus Streptosolen in a tribe Browallieae.
A total of at least 17 different species have been described, of which only six are likely to be recognized as valid, however.
- Browallia americana L.
- Browallia demissa L.
- Browallia elata L.
- Browallia grandiflora Graham
- Browallia speciosa L.
Occurrence
The species of the genus come from southern Arizona through Mexico, Central America prior to the Andean South America, and to Bolivia. They grow at altitudes 500-2600 m. Browallia americana and Browallia speciosa are sometimes drawn as ornamental plants and can be found as a cultural refugee in disturbed habitats.