[+] Cones pendulous, their scales persistent; bracts smaller than the scales; leaves jointed upon a prominent persistent base, solitary.
2. Picea. Leaves sessile, keeled on both sides (tetragonal).
3 Tsuga. Leaves petioled, flat.
[+][+] Cones erect; bracts longer than the scales; leaf-scars not prominent.
4. Abies. Scales of the large cone deciduous. Leaves persistent, solitary, keeled beneath.
5. Larix. Scales of the small cone persistent. Leaves mostly fascicled, flat, deciduous.
Tribe II. TAXODIEÆ. Fertile aments of several spirally arranged imbricated scales, without bracts, becoming a globular woody cone. Ovules 2 or more at the base of each scale, erect. Leaves linear, alternate; leaf-buds not scaly.
6. Taxodium. Seeds 2 to each scale. Leaves 2-ranked, deciduous.
Tribe III. CUPRESSINEÆ. Scales of the fertile ament few, decussately opposite or ternate, becoming a small closed cone or sort of drupe. Ovules 2 or more in their axils, erect. Cotyledons 2 (rarely more). Leaves decussately opposite or ternate, usually scale-like and adnate, the earlier free and subulate; leaf-buds not scaly.
[*] Monœcious; fruit a small cone; leaves opposite and foliage more or less 2-ranked.