Myrtillifolia: Answers to key questions in Conifers & Catkin-Bearing Trees and Shrubs of Saskatchewan, Fascicle 5, Flora of Saskatchewan by Anna Leighton leading to this species. The answers are in the order you would normally work through the key. 

	Catkins usually flowering as leaves emerge, sometimes just before leaves emerge or throughout the season, subtended by small green leaves of the flowering branchlet that supports them.  NOT  [Catkins usually flowering before leaves emerge, borne directly on bare branches (sessile) and subtended by 1 - 3 short, greenish or brownish, caducous bract-like leaves]
	Low to tall shrubs or trees; not confined to subarctic regions.  NOT [Dwarf shrubs <= 0.15 m (15 cm) tall; subarctic regions]
	Shrubs, usually with several stems; ovaries glabrous or hairy.   NOT  [Trees, with a single trunk, or with several trunks of tree stature; ovaries glabrous]
	NOT [Plants flowering as leaves emerge or throughout the season, often bearing branched catkins; leaf blades linear or strap-shaped, 9 – 14 – 24 times longer than wide, up to 11 mm wide with margins remotely spinulose-serrulate, the teeth widely spaced; hairs on leaves white, ferruginous hairs lacking; plants forming extensive colonies by root shoots]
	Petioles without glandular dots or lobes at distal end, or with occasional, inconspicuous dots; floral bracts not as above, if conspicuous and pale, then not deciduous.  NOT [Petioles with glandular dots or lobes at distal end; floral bracts pale tawny, 1.2 – 4 mm, conspicuous during flowering, deciduous after flowering]
	Ovaries glabrous. NOT [Ovaries hairy].
	Lower surfaces of leaf blades not glaucous, usually glabrous but sometimes hairy. NOT [Lower surfaces of leaf blades glaucous, sometimes obscured by dense hairs.]
	Native, low, mid to tall shrubs, up to 7 m tall; leaf blades not as above: if glabrous on both surfaces, then largest medial leaf blades smaller. NOT [Introduced tall shrubs or trees up to 12 m high, rarely escaping cultivation; juvenile and largest medial leaf blades glabrous on upper and lower surfaces; largest medial leaf blades dark green and highly glossy above, 55 – 82 – 113 mm long.]
	Lower surfaces of juvenile leaf blades glabrous or, if hairy, the hairs white or with some ferruginous; not known to occur in the MacFarlane R. area south of Lake Athabasca. NOT [Lower surfaces of juvenile leaf blades hairy, the hairs white; MacFarlane River, south of Lake Athabasca.]
	Floral bracts 0.4 – 1.1 mm, brown, bicolor, black, or tawny; catkins moderately to very densely flowered; stipules on late leaves 0.2 – 5 mm; petioles 3 – 4 – 7 mm; juvenile leaves reddish or yellowish green; widely distributed. NOT [Floral bracts 1 – 2 mm, dark brown; catkins densely flowered; stipules on late leaves 2 – 3.3  - 6.5 mm; petioles 3 – 9 – 17 mm; juvenile leaves yellowish green; Battle Creek area of Cypress Hills.]
	Styles up to 0.7 mm; shrubs usually decumbent, to 0.6 m tall; stipules on late leaves rudimentary or foliaceous, 0.2  - 1.8 (5.0) mm; lower surfaces of juvenile leaf blades glabrous; margins of proximal leaves crenate; leaf blade lower surfaces glabrous, and upper surfaces glabrous or rarely sparsely and minutely hairy on midribs. NOT [Styles up to 1.6 mm; shrubs erect, 1 – 7 m tall; stipules on late leaves foliaceous, 1 – 5 mm; lower surfaces of juvenile leaf blades glabrous or hairy with white or some ferruginous hairs; margins of proximal leaves serrulate or entire; leaf blade lower surfaces glabrous or pilose, and upper surfaces usually sparsely pubescent, pilose or silky, sometimes hairy only on midribs.]

Salix: Answers to key questions in Conifers & Catkin-Bearing Trees and Shrubs of Saskatchewan, Fascicle 5, Flora of Saskatchewan by Anna Leighton leading to this genus. 

	shrubs or trees; NOT [trees]
	buds covered by 1 scale; NOT  [buds covered by 3-10 scales]
	buds scale not resinous; NOT [bud scale usually resinous]
	catkins sessile or terminating flowering branchlets; NOT [catkins sessile]
	catkins erect, spreading, or +/- pendulous; NOT [catkins pendulous]
	floral bracts entire, erose, bifid, or irregularly toothed; NOT [floral bracts deeply cut]
	perianth reduced to an adaxial nectary (rarely also an abaxial nectary, then the 2 nectaries distinct or connate into a shallow cup); NOT [perianth reduced to a non-nectariferous, cup-shaped or shallow saucer-shaped floral disc]
	stamens 1, 2, or 3 – 10; NOT [stamens 6 – 60 (70)]
	capsules obclavate to ovoid or ellipsoid; NOT [capsules narrowly ovoid to spherical, with the floral disc persistent at base]
	capsules 2-valved; NOT [capsules 2 - 4 valved]

Salicaceae: Answers to key questions in Budd's Flora  leading to this family. 

	shrubs or trees; NOT [herbs]
	flowers with only one floral ring, with sepals but not petals
	male flowers, at least, in catkins or aments; NOT [flowers not in catkins or aments]
	seeds each with a tuft of hairs; NOT [seeds without a tuft of hairs]