Rosidae

The rose -like (Rosidae ) form a subclass of angiosperms ( Magnoliophyta) in some classifications. They are essentially the Rosids clade. The various groups have produced a wide variety of flowers and growth habits, and many are as crops of importance.

Features

The flowers are mostly radial symmetry, rare dorsiventrally. They have a cyclic structure, five- or four- multiplicity. They have a double perianth: the calyx corresponds to the perianth of the Magnoliopsida and the simple Rosopsida. The petals have been re-designed from an outer stamen circle. The petals are usually free, that is not attached, so they were asked earlier in a development stage " Dialypetalae ". The androecium usually consists of two circles ( Diplostemonie ). In some kinship groups, it is come to the secondary, centripetal or centrifugal polyandry. In wind-pollinated groups, the petals and stamens can also be reduced again (secondary Apetalie and Haplostemonie ).

The pollen grains are two - or three nuclei. They are originally tricolpate that another figure is very diverse.

In the basal orders are the carpels still available ( choricarpy ), but it outweigh intergrown carpels ( coenocarpy ). The ovules have two integuments and are crassinucellat. The secondary endosperm usually develops nucleär.

The plastids of the sieve tubes mainly belong to the S- type. Phytochemically the Rosidae are characterized by the presence of trihydroxylated flavonoids (such as myricetin and Leucodelphinidin ), ellagic acid and Ellagi and gallotannins. Largely or completely absent here Benzylisochinolinalkaloide, betalains, iridoids, indole alkaloids.

In this group often occur endosymbiosis with nitrogen-fixing prokaryotes to air ( Rhizobium, actinomycetes ), but these are limited to certain kinship groups: Rosales, fagales, Fabales, Cucurbitales.

Crops

Of great economic importance are the divisions: Rosales, with plenty of fruits such as apple, pear, cherry and wine; Furthermore, the Fabales with legumes beans, peas, lentils, soybeans, and peanuts further; to the Sapindales include citrus fruits; to the Malpighiales the Common flax or flax, the rubber tree and cassava. The fagales include many timbers of temperate latitudes.

System

• Subclass Rose something similar ( Rosidae) basal groups No inclusion in an order

• Vitales with the single family: Grape Family ( Vitaceae )

• No inclusion in an order

• Jochblattartige ( Zygophyllales )
• Spindle Tree-like ( Celastrales )
• Malpighienartige ( Malpighiales )
• Sorrel -like ( Oxalidales )
• Pea -like ( Fabales )
• Rose -behaved ( Rosales )
• Pumpkin -like ( Cucurbitales )
• Beech- ( fagales )

• Huerteales
• Kreuzblütlerartige ( Brassicales )
• Malvenartige ( Malvales )
• Soap tree -like ( Sapindales )