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Pakistan | Family List | Brassicaceae

Draba Linn., Sp. Pl. 642. 1753. Gen. Pl. ed. 5:291.1754; Benth. & Hook.f. Gen.Pl.1:74.1862; Boiss. l.c. 292; Hook. f., l.c. 141; Schulz in Engl. & Prantl, l.c. 500; Tolmachev in Kom., l.c. 371; R. Pohle in Fedde, Repert. 32:1-225.1925; O.E. Schulz in Engler, Pflanzenr. 89 (IV. 105) : 1-343.1927; Coode & Cullen in Davis, l.c. 413; Hedge in Rech. f., l.c. 178.

Draba korschinskyi
Illustration

Credit: Shaukat & Azmat

Annual to perennial herbs, often caespitose, usually hairy with branched or simple hairs. Aerial stem scapose or leafy. Basal or radical leaves usually densely rosulate, shortly stalked to sessile (very rarely long stalked) ; cauline leaves usually sessile; all leaves simple, entire to sinuate-dentate. Racemes usually ebracteate, corymbose. Flowers small, sometimes mediocre, yellow or whitish (often drying white), rarely lilac, pedicellate. Sepals subequal, not or slightly saccate at base. Petals obovate-cuneate, apex subemarginate or entire. Stamens 6 (sometimes outer 2 abortive), without appendages (rarely outer filaments 1-dentate); anthers ovoid or oblong, obtuse. Nectar glands various, lateral 2-4 lobed, often lobes joined forming a horse-shoe shaped structure; middle glands usually absent. Ovary often broadly or narrowly elliptic, 4-many ovuled; style usually distinct with short stigma. Siliculae usually short (rarely siliquiform), ovate, suborbicular to elliptic or lanceolate, broadly septate, bilocular, dehiscent, straight or contorted, usually compressed; valves plane to subconvex, often with a distinct mid-vein, glabrous or hairy; septum membranous, complete, usually not veined; seeds often biseriate in each locule, 2- many, ovate or elliptic, often pale brown, not mucilaginous when wet; radicle accumbent.

Nearly 300 species, chiefly of Arctic and Alpine regions, extending also in temperate zone and at higher elevations into the tropics. Only 23 species are recorded from our area.

A very natural group and with highly variable species. Recognition of infra specific ranks and even species, should be very cautiously done. It is surely unnecessary and useless to describe a species and at the same time to recognize one or more `varieties' of it in the same one gathering, when these `varieties' or variants are part of the natural variability inherent in the population.

Furthermore, in the absence of petals, there is no difference between this genus and Erophila, and Draba tenerrima O.E. Schulz. can be placed in both the genera because it has no petals. However, Draba tenerrima looks more like Erophila and there-fore, has been transferred to that genus.


1 Flowering shoot aphyllous, scapose (rarely 1-2 leaved)   (2)
+ Flowering shoots leafy, usually many leaved (rarely 1-2 leaved)   (13)
       
2 (1) Seeds large, c.3 mm long; fruits 12-20 mm long. Leaves Long, needle-like   Draba hystrix
+ Seeds small usually c.1 (-2) mm or less long; fruits usually up to 10 mm long. Leaves not needle-like   (3)
       
3 (2) Petals (4.5-) 5-6 mm long   (4)
+ Petals (1.5-) 2.5-4 mm long   (7)
       
4 (3) Racemes 5-10-flowered (rarely 3 or 12 flowered) seeds c.1 mm long   (5)
+ Racemes 15-30-flowered (rarely less); seeds c.0.5 mm long   Draba olgae
       
5 (4) Plants ± floccose-hairy with short, branched soft white hairs; siliculae usually 10-15 mm long   Draba tibetica
+ Plants ± ciliately hairy with simple and branched hairs; siliculae 3-8 mm long   (6)
       
6 (5) Leaves with ± 3 longitudinal veins   Draba trinervis
+ Leaves with 1 mid-vein   Draba affghanica*
       
7 (3) Plants, especially leaves, floccose with short, branched or simple soft whitish hairs   (8)
+ Plants ± ciliately hairy with simple or branched hairs   (9)
       
8 (7) Siliculae 5-8 mm long, lanceolate or oblong-elliptic, somewhat contorted, compressed; style 1-1.5 mm long   Draba winterbottomii
+ Siliculae usually 3-4 (-5) mm long, ovoid, inflated; style c. 0.5 mm long   Draba korschinskyi
       
9 (7) Petals c.2.5 mm long   Draba melanopus
+ Petals (3-) 4-6 mm long   (10)
       
10 (9) Siliculae linear or elliptic-oblong, compressed   (11)
+ Siliculae ovoid or elliptic- ovate, sub inflated or Sub-compressed   (12)
       
11 (10) Siliculae 5-10 mm long, 2.5-3.5 mm broad, oblong- elliptic; pedicel 4-6 mm long in fruit   Draba setosa
+ Siliculae (submature). Ovate-lanceolate c. 6 mm long, 2-3 mm broad; pedicel 8-10 mm long in fruit   Draba pakistanica
       
12 (10) Petals 2.5-3 mm broad; basal leaves 3-5 mm long, 1 mm broad   Draba cachemirica
+ Petals c. 1.5 mm broad ; basal leaves (2.5-) 5-25 mm long, (1-) 2-3 (-4) mm broad   Draba oreades
       
13 (1) Annuals   (14)
+ Perennials   (16)
       
14 (13) Petals 1-2 mm long; siliculae 5-8 mm long, c. 2.5 (-3) mm broad, oblong-elliptic   (15)
+ Petals c. 4 mm long; siliculae 8-20 mm long c.2 mm broad   Draba stenocarpa
       
15 (14) Racemes 3-5-flowered ; petals c. 1 mm long, about as long as sepals   Draba ellipsoidea
+ Racemes many flowered; petals c. 2 mm long, slightly longer than the sepals   Draba nemorosa
       
16 (13) Seeds sub-biseriate, large, c.2 mm long, obscurely winged   Draba aubrietoides
+ Seeds biseriate, small, c. 1 mm long, not winged or margined   (17)
       
17 (16) Plants not caespitose; stem usually decumbent, sparsely branched; fruits 10-20 mm long, 2.5-3 mm broad   Draba falconeri
+ Plants caespitose, usually erect and branched from the base; siliculae usually up to 10 mm long and 2 mm broad   (18)
       
18 (17) Plants tomentose with short, branched white hairs (rarely mixed with long simple hairs)   (19)
+ Plants ± ciliately hairy with simple or branched hairs   (22)
       
19 (18) Sepals persistent in fruit; siliculae 3-4 mm long, 2.5-3 mm broad, ovate-orbicular, not contorted, glaprous   Draba ludlowiana
+ Sepals caducous; siliculae (3.5-) 6-14 mm long, 1.5-2 mm broad, oblong-linear, ± pubescent and contorted   (20)
       
20 (19) Homotrichous (with short and branched hairs)   (21)
+ Heterotrichous (short branched hairs mixed with simple or forked long hairs)   Draba lasiophylla
       
21 (20) Seeds 16-20 in each locule   Draba lanceolata
+ Seeds 3-6 in each locule   Draba glomerata
       
22 (18) Siliculae ovate-oblong, 2.5-5 mm long; pedicel 4-6 mm long in fruit racemes capitate, congested, up to 4 (-5) cm long in fruit   Draba altaica
+ Siliculae linear, 6-14 mm long; pedicel 15-25 (-30) mm long in fruit ; racemes lax, up to 15 cm long in fruit   Draba gracillima

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