PICEA
SPRUCE-FIRS
- Picea, Link, Abhandl. Akad. Wiss. Berlin, 1827, 179 (1830); Bentham et Hooker, Gen. Pl. iii. 439 (1880); Masters, Jour. Linn. Soc. (Bot.) xxx. 28 (1893).
- Abies, Linnæus, Gen. Pl. 294 (in part) (1737); D. Don in Lambert, Pinus, vol. iii. (1837), ex Loudon, Arb. et Frut. iv. 2293 (1838).
This genus includes the spruce-firs, which in England, following the practice of Don and Loudon, are still often called Abies. However, all botanists in England, on the Continent, and in America apply the term Picea to the spruces, and Abies to the silver firs.
Tall evergreen trees belonging to the tribe Abietinese of the order Coniferæ, with shoots of only one kind, bearing in spiral order peg-like projections ("pulvini"), from which the leaves arise singly. The needle-like leaves are either tetragonal or flattened in section, and persist for many years, rendering the foliage very dense. At the ends of the leading shoots there is a terminal bud, with 2-5 side buds directly under it; the buds are dry and not resinous.
Flowers monœcious. Male flowers solitary in the axils of the uppermost leaves, ovoid or cylindric, short-stalked, surrounded at the base with scale-like bracts, composed of numerous stamens spirally arranged, each with 2 pollen-sacs opening longitudinally, and a connective prolonged into a toothed crest. Pollen grains with 2 air-sacs. Female flowers solitary, terminal, erect, stalked, with a few empty scales at the base; composed of 2 series of scales, the bracts small and membranous, and the ovular scales bearing at their base 2 inverted ovules. Cones: generally becoming pendulous, but in certain species remaining erect or spreading; cylindrical or ovoid, with the bracts minute and concealed, and the scales enlarged and firm in texture, with entire or denticulate margins, and bearing on their inner surface 2 winged seeds. The cones are ripe in the first season, and after dispersal of the seed (the scales persisting on the axis) fall off in the following winter, or remain in some species much longer on the tree. The cotyledons are 5–15 in number, 3-sided, and serrate in margin.
Species of spruce occur in Europe, Asia Minor, the Caucasus, Siberia, Mongolia, China, Japan, the Himalayas, and in North America. The genus is marked out into two natural sections by the character of the leaves. These are defined by Willkomm as follows:—
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