Species: Draba breweri var. cana (Rydb.) Rollins

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Draba breweri var. cana (Rydb.) Rollins

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TAXONOMY

Family:

Brassicaceae

Genus:

Draba

Species Synonyms:

Draba cana Rydb.
Draba lanceolata auct. non Royle
Draba stylaris J. Gay ex W.D.J. Koch

Common Names:

lanceleaf draba
hoary whitlowgrass
lanceolate draba
hoary whitlow grass

DISTRIBUTION

Canada:

Yukon Territory - Mackenzie District (Northwest Territories) - Hudson Bay - Labrador, south to British Columbia - Alberta - northern Saskatchewan - southern Ontario - Quebec

Saskatchewan:

northern Saskatchewan; Lake Athabasca to Hasbala Lake

Ecoregion:

Tazin Lake Upland, Selwyn Lake Upland

HABITAT

Saskatchewan:

calcareous cliffs and outcrops

RARITY STATUS

Provincial Status According
to Harms (2003):

Threatened

Nature Conservancy Status:

G5 S1

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Draba breweri var. cana is threatened in Saskatchewan because it is rare and population sizes vary. This species is likely frequently overlooked, especially when not in flower.

SPECIES DESCRIPTION

Height:

10 – 30 cm

Roots:

taproot

Stems:

caudex simple or branching; stems perennial, 1 – several, tufted, ascending or erect, simple or branched, thin, green-gray to purple, pubescence of stellate, bifid and simple hairs

Leaves:

basal and cauline; basal rosette dense, leaves 5 – 20 mm long, 2 – 8 mm wide, narrowly oblanceolate, tomentum stellate, margin entire or very sparsely toothed; cauline leaves usually 5 – 8, at least halfway up the stem, alternate, sessile, 5 – 20 mm long, elliptic to ovate, tomentum stellate, entire to very sparsely toothed

Inflorescence:

raceme, often leafy bracted at base, about half the length of the stem in fruit; 10 – 50 flowered; pedicels < 2 times the length of the pod;

Flowers:

calyx about 2 mm long, pilose; corolla 3 – 5 mm long, cruciform, white; style 0.4 – 1.0 mm

Fruits:

silique 6 – 14 mm long, 1.5 – 2 mm wide, narrowly lanceolate, twisted at maturity, stellate pubescence; pedicels ascending in fruit; seeds 20 - 48 in two rows, reddish brown

DRABA KEY IN SASKATCHEWAN

1 Flowers yellow; stems very leafy or pedicels 2 – 4 x as long as pod	2
1 Flowers white; stems with less than 10 leaves and pedicels various	3

2 Stem leaves usually more than 10; pedicels shorter than pod	D. aurea
2 Stem leaves 1 – 5; pedicels 2 – 4 x as long as pod	D. nemorosa

3 Stem leaves all or mostly opposite; inflorescence subumbellate in fruit	D. reptans
3 Stem leaves alternate; inflorescence racemose in fruit	4

4 Caudex absent; stem leaves on lower 1/3 of plant; pedicels 2 – 4 times as long as pod	D. nemorosa
4 Caudex present; stem leaves usually at least 1/2 way up stem; pedicels rarely 2 times as long as pod	5

5 Stem leaves less than 5; fruiting pedicels spreading-ascending; mature siliques broadly lanceolate, not twisted, with thick coat of minute hairs; seeds at most 36	D. cinerea var. cinerea
5 Stem leaves usually 5 – 8; fruiting pedicels strongly ascending; mature siliques narrowly lanceolate, twisted, with stellate hairs; seeds 20 - 48	D. breweri var. cana