Species: Atriplex powellii S. Wats.

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Atriplex powellii S. Wats.

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TAXONOMY

Family:

Chenopodiaceae

Genus:

Atriplex

Species Synonyms:

none

Common Names:

Powell’s saltbush
Powell’s orache
Powell’s saltweed
Powell’s silverscale

DISTRIBUTION

Canada:

southern Alberta – southwestern Saskatchewan

Saskatchewan:

southwestern Saskatchewan; Cabri Lake - Lower Frenchman River Valley - Wood Mountain

Ecoregion:

Mixed Grassland

HABITAT

Saskatchewan:

dry, subsaline clay flats

Associated species:

gumweed, hoary tansyaster, lambsquarter, narrowleaf goosefoot, silverscale saltbrush, western seepweed, yard knotweed

RARITY STATUS

Provincial Status According
to Harms (2003):

Endangered

Nature Conservancy Status:

G4G5 N2 S1

Saskatchewan Species at
Risk Status:

Endangered

COSEWIC Status:

None

Powell’s saltbush is endangered in Saskatchewan because it is regionally restricted in the province. Powell’s saltbush is usually locally numerous, but within limited areas. Possible threats to this species include human development and fragile habitat.

SPECIES DESCRIPTION

* kranz-type venation: appears as a dark green net pattern when leaf surface is lightly scraped with a sharp blade under 10X magnification

Height:

5 – 100 cm, may be as wide as tall with branching

Roots:

taproot

Stems:

annual, herbaceous, erect, branched at base, curved upwards, shallowly ridged, straw-coloured

Leaves:

alternate, lowest leaves may be opposite, lower leaves slender, short-stalked; upper leaves stalkless, 1 – 3 cm long, almost as wide as long, ovate, base rounded or slightly wedge-shaped, conspicuously 3-nerved, kranz-type venation, silvery-gray mealy

Inflorescence:

male and female flowers on the same plant

Flowers:

male flower sepals and petals 5-parted, stamens 5; female flowers sessile, bracts 2, 3 – 4 mm long, 3 – 4 mm wide, oblong, thick, appendaged, united to tip, irregularly toothed

Fruits:

seeds to 1.6 mm long, flat, light brown or yellowish

ATRIPLEX KEY FOR SPECIES FOUND IN SASKATCHEWAN

* kranz-type venation: appears as a dark green net pattern when leaf surface is lightly scraped with a sharp blade under 10X magnification

1 Plants perennial, woody at least in part; leaves with kranz-type venation	2
1 Plants annual, herbaceous throughout; leaves with kranz-type or other venation	3

2 Plants woody at base; fruiting bracts not winged lengthwise	A. gardneri
2 Plants woody throughout; fruiting bracts prominently 4-winged lengthwise	A. gardneri var. aptera

3 All leaves stalkless	4
3 At least some leaves stalked	6

4 At least some parts of plant usually mealy, covered in bran-like scales or otherwise hairy; leaf base wedge-shaped, square or heart-shaped; female flowers in dense, head- like clusters in terminal and axillary spikes	A. truncata
4 Plants hairless or nearly so; leaves tapering to base; female flowers solitary or clustered in leaf axils	5

5 Leaves and stems green and hairless	A. dioica
5 Leaves with a bluish waxy coating, sparingly mealy when young; stems reddish tinged	A. suckleyi

6 Plants with kranz-type venation	7
6 Plants with normal dicot venation	9

7 Bracts spoon-shaped, 4 – 8 mm long, margin toothed, usually bony and hard	A. argentea var. argentea
7 Bracts wedge-shaped or oblong, 2 – 3.5 mm long, not toothed or hard and	8

8 Leaves nearly stalkess, not conspicuously nerved; bracts wedge-shaped, 2 – 3 mm long	A. truncata
8 Leaves with slender stalks, conspicuously 3-nerved, bracts oblong, 3 – 4 mm long	A. powellii

9 Leaves green; bracts nearly round, entire	A. hortensis
9 Leaves with bran-like scales or mealy; bracts not rounded, toothed	10

10 Leaves arrowhead-shaped; seeds circular	A. prostrata
10 Leaves oval to lance-shaped or linear; seeds elliptic	A. patula