Picea mariana
 
Black Spruce

Leaf Side B

Duck Mountain Provincial Park
15-May-2015

Note the leaves are 4-sided.

The key answers below are taken from Conifers & Catkin-Bearing Trees and Shrubs of Saskatchewan by George Argus, Vernon Harms, Anna Leighton, and Mary Vetter.  This book is published jointly by Flora of Saskatchewan Association and Nature Saskatchewan.

Mariana: Answers to key questions leading to this species. 

Seed cones ovoid-subglobose, persisting on tree for several years, 1.5-2.5 (3.5) cm long; seed cone scales 8-12 mm long, margin at apex irregularly toothed; needles 0.6-1.5 (2) cm long, mostly blunt-tipped, glaucous, blue- to grey-green; twigs and bud scales puberulent.  NOT [Seed cones ovoid-oblong, deciduous, falling the first winter, 2.5-6 (7) cm long; seed cone scales 10-16 mm long, margin near apex +/- entire; needles (0.8) 1.5-2 (2.5) cm long, mostly sharp-pointed, glaucous, green or blue-green; twigs and bud scales glabrous.]

 

Picea: Answers to key questions leading to this genus. 

Needles borne singly along branches, not in fascicles scaly-sheathed at base or on short shoots.  NOT [Needles on year-old and older branches borne either in groups (fascicles) of 2 with each fascicle scaly-sheathed at base at least when young, or in clusters of 12-25 on short shoots with clusters not scaly sheathed.]

Needles 4-angled in cross-section, either sharp-pointed or blunt-tipped, rigid; seed cones falling as a unit, not disintegrating by shedding scales individually from cone axis; twigs conspicuously roughened by decurrent, spreading or appressed, peg-like projections (pulvini) persisting after needles fall.  NOT [Needles flattened, frequently grooved adaxially, usually rounded or notched at apex, flexible; seed-cones not falling whole but scale by scale, leaving naked cone axes persisting as erect "spikes" on branches; twigs not roughened by decurrent, projecting, peg-like leaf-bases.]

 

Pinaceae: Answers to key questions leading to this family. 

Leaves needle-like, alternate or fascicled/clustered, shed individually from branchlets (usually shed as fascicles in Pinus); seed cone scales imbricate; seed cones dry; seeds adaxial and 2 per scale.  NOT [Leaves needle-like or scale-like, alternate, opposite or whorled, persistent on shoots, shedding with branchlets with age; seed cone scales fused or imbricate; seed cones berry-like (Juniperus) or dry (Thuja); seeds adaxial or terminal and 1-20 per scale.]