| Arabis | |
|---|---|
| Arabis ferdinandi-coburgii | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Rosids |
| Order: | Brassicales |
| Family: | Brassicaceae |
| Genus: | Arabis Adans. |
| Species | |
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See text |
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Arabis ( /ˈɛərəbɨs/),[1] or rockcress, is a genus of flowering plants, within the family Brassicaceae, subfamily Brassicoideae.
Though traditionally recognized as a large genus with many Old World and New World members, more recent evaluations of the relationships among these species using genetic data suggest there are two major groups within the old genus Arabis. These two groups are not each others' closest relatives, so have been split into two separate genera. The Old World members all remain in the genus Arabis, whereas most of the New World members have been moved into the genus Boechera, with only a few remaining in Arabis.
The species are herbaceous, annual or perennial plants, growing to 10-80 cm tall, usually densely hairy, with simple entire to lobed leaves 1-6 cm long, and small white four-petalled flowers. The fruit is a long, slender capsule containing 10-20 or more seeds.
Some species, notably A. alpina, are cultivated as ornamental plants in gardens. Many others are regarded as weeds.
Some species are rare, such as Arabis fecunda, which is endemic to Montana and known from only 19 occurrences.[2]