All Floras      Advanced Search
Page 268 Login | eFloras Home | Help
Pakistan | Family List | Brassicaceae

Arabidopsis Heynh. in Holl & Hynh., Fl. Sachsen. 1: 538. 1842. Schulz in Engl. & Prantl, l.c. 640; Busch in Kom., l.c. 76; Hedge in Davis, l.c. 480; in Rech. f., l.c. 328.

Arabidopsis stricta
Illustration

Credit: Azmat

Annual, biennial or perennial herbs, branched mostly from the base, erect or suberect, usually densely hairy with simple and branched, intermixed hairs. Basal leaves often rosulate, stalked, obovate-oblong, dissected to almost entire; cauline leaves sessile, often broad based and auricled, semiamplexicaul, sometimes cuneate below, dentate to entire. Racemes corymbose, lax in fruit and elongating. Flowers small, white or pinkish, rarely yellow; pedicels not thickened, filiform, ascending or spreading in fruit, often elongated. Sepals not saccate at base. Petals slightly to about twice as long as the sepals, rarely suppressed or absent. Stamens 6, rarely 4; filaments not appendaged; anthers ovoid, obtuse. Lateral nectar glands semiannular or annular, rarely semiglobose; middle present, often torose, sometimes joining the laterals. Ovary linear, 20-100-ovuled; stigma depressed, obscurely bilobed, usually on short style. Siliquae linear, often curved, compressed-terete, glabrous or hairy ; valves usually membranous, subconvex, 1-veined; septum membranous, usually not veined; seeds 1-seriate, ovoid, mucilaginous when wet (very rarely not mucilaginous) ; radicle generally incumbent.

About 15 species, chiefly Asian; 10 species recorded from our area.

A genus more close to Arabis L. in habit and siliquae, but seeds mostly mucilaginous when wet, flowers smaller, valves subconvex to terete and radicle incumbent. Need of revaluation of its generic status with Microsisymbrium, Arabis andTorularia has already been discussed elsewhere also.


1 Cauline leaves narrowed below, neither auricled nor amplexicaul at base   (2)
+ Cauline leaves broad at base, often slightly auricled and amplexicaul   (5)
       
2 (1) Siliquae 10-20 mm long. Plants usually small, ± glabrous above; basal leaves entire to subdentate   Arabidopsis thaliana
+ Siliquae 50-70 mm long . Plants usually tall, hairy or canescent; basal leaves pinnatifid   (3)
       
3 (2) Plants simple or sparingly branched form the base; basal leaves rosulate; siliquae acute with a conspicuous style.   (4)
+ Plants densely branched above; basal leaves loosely or not rosulate; siliquae blunt at the apex with inconspicuous or short style   Arabidopsis russelliana
       
4 (3) Basal leaves much elongated, slightly shorter than the flowering stem, minutely pubescent; flowers c. 5 mm across   Arabidopsis taraxacifolia
+ Basal leaves not so elongated, much shorter than the flowering stem, canescent with conspicuous long and short hairs; flowers c. 3.5 mm across   Arabidopsis wallichii
       
5 (1) Flowers yellow   Arabidopsis pumila
+ Flowers white or pinkish   (6)
       
6 (5) Siliquae 10-18 mm long, densely pubescent; pedicel 2-3 mm long in fruit   Arabidopsis lasiocarpa
+ Siliquae(20-) 30-60 mm long, ± glabrous; pedicel(5-) 8-15 (-20) mm long in fruit   (7)
       
7 (6) Annual; cauline leaves greenish, entire, slightly narrowed at base, oblong   Arabidopsis stricta
+ Perennial; cauline leaves densely pubescent, whitish in appearance, broad at base, often slightly auricled dentate to entire   (8)
       
8 (7) Plants somewhat caespitose, 2-5 cm tall in fruit; cauline leaves 0-4 only   Arabidopsis brevicaulis
+ Plants 15-40 cm tall, not caespitose; cauline leaves many   (9)
       
9 (8) Racemes ebracteate (rarely 1-2-bracteate below); siliquae usually erect and straight   Arabidopsis mollissima
+ Racemes bracteate, often up to the apex; siliquae usually subspreading and slightly curved   Arabidopsis himalaica

  • List of lower taxa


     

    Related Objects  

    Flora of China  
  • O'KANE, Jr., S.L. & I.A. AL-SHEHBAZ. 2003. Phylogenetic position and generic limits of Arabidopsis (
  • PDF
  • PDF File
  • PDF

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