All Floras      Advanced Search
Page 179 Login | eFloras Home | Help
Pakistan | Family List | Brassicaceae | Arabis

Arabis bijuga G. Watt in Journ. Linn. Soc. Bot. 18:378. 1881. Hedge in Rech. f., l.c. 210.

  • Arabis nuristanica*
  • Arabis pangiensis*

    Perennial, 15-40 cm tall, subglabrous to hairy with short branched, somewhat stellate hairs. Radical leaves like in the above species; cauline leaves narrow, oblong, sometimes narrowed at the base also, 1-3 cm long, 2-6 (-8) mm broad, sessile, semi-amplexicaul. Flowers usually large, c. 1 cm across, often with diverging pairs of c. 14 mm long petals; pedicels usually elongated, up to 20 mm long, spreading. Siliquae and seeds as in the previous species.

    An intermediate species between A. amplexicaulis Edgew. and A. pangiensis Watt, and forms reaching both sides occur especially when the plants are somewhat glabrous and densely hairy respectively.

    Differs from A. amplexicaulis by its slightly larger flowers (with petals c. 14 mm long) short stellate hairs, and narrow cauline leaves; also differs from Arabis pangiensis by its larger stature including flowers, and usually with several cauline leaves.

    Type: N.W. Himalaya, Chamba, Pangi, 2550 m., G. Watt 899 (E).

    Distribution: N.W. Himalaya and Pakistan. Fl. Per.: May-July.

    The absence of flowers the species is distinguished from Arabis amplexicaulis Edgew., by its short stellate hairs, like those in In tArabis pangiensis Watt.

    The type specimens of A. bijuga Watt and Arabis pangiensis Watt are from the same place (Pangi, Chamba) in N.W. Himalaya, and look remarkably distinct from each other; but are they actually different or just two extreme forms of the same taxon ? This doubt arises because of the following reasons: 1. They are from the same place, 2. There are specimens, with short stellate hairs on leaves like those in the latter species but habit like that of the former species 3. They both grow on rocks, the former on open rocks, and the latter perhaps in rock crevices. This may be the reason of the former being tall and less hairy, and the latter short and more hairy. This type of variation is not uncommon in other species of Arabis. Elsewhere also such forms have been noticed where species are highly polymorphic and variable, and unless we know the entire range of variations, nothing can be said with certainty with the help of the type specimens only. 1 have a feeling that both the above taxa belong to one single species, and this view is supported by the presence of intermediate specimens, all having similar hairs, usually short and branched or stellate, from subglabrous to densely hairy conditions, and their leaves are usually narrow. Thus they are remarkably a distinct group from that of Arabis amplexicaulis Edgew., where the plants usually have longer, simple, forked or branched hairs and somewhat broader leaves.

    The A. pangiensis- Arabis bijuga complex problem can only be solved with further experimental works with freshly collected seeds. Arabis amplexicaulis and A. bijuga have often been confused and the latter sometimes wrongly identified, because of its similar habit.


     

    Related Objects  

    Flora of China  
  • Illustration
  • Illustration

  •  |  eFlora Home |  People Search  |  Help  |  ActKey  |  Hu Cards  |  Glossary  |