Picea
Picea A. Dietrich
Picea is a genus of about 35-40 species. Most are native in north temperate regions (primarily North America and Eurasia).
Page & Rushforth (1986) enumerate at least 19 species that are generally cultivated in Europe, either for commercial (sawn timber or paper pulp) or ornamental reasons. Several species of Picea are cultivated for timber production in Belgium as well, particularly in the Ardennes (or, more rarely, as ornamentals in public or private gardens). Lambinon & al. (2004) provide a key for the identification of the following taxa: Picea abies, P. omorika (Pančić) Purkynĕ, P. orientalis (L.) Link, P. pungens Engelm. and P. sitchensis. A very useful identification key for the species cultivated in Belgium is available here: http://www.arboretumwespelaar.be/userfiles/file/pdf/Key_Picea_JDL.pdf.
To our knowledge, so far only the following three species have been reported as self-reproducing in Belgium. Others probably have been overlooked so far.
1. Needles distinctly quadrangular in section with four equal sides. Buds non-resinous === Picea abies
1. Needles flattened to slightly rhombic in section with two sides (obviously longer than wide). Buds resinous or not === 2
2. Twigs glabrous. Leaves usually very pungent. Buds resinous === P. sitchensis
2. Twigs hairy. Leaves with a short mucro but not pungent. Buds usually not resinous (or only slightly so) === P. omorika
Literature:
Alden B. (1987) Taxonomy and geography of the genus Picea. Int. Dendrol. Soc. Year Book 1986: 85-96.
Christensen K.I. (2000) Coniferopsida. In: Jonsell B. (ed.), Flora Nordica, vol. 1. The Bergius Foundation, Stockholm: 91-115.
De Koning J., Van den Broek J.W., Van de Laar H.J. & Fortgens G. (2000) Nederlandse dendrologie (13e druk). H. Veenman & zonen, Ede: 585 p.
Farjon A. (1990) Pinaceae: drawings and descriptions of the genera Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga, Cathaya, Pseudotsuga, Larix and Picea. Regnum Vegetabile 121. Königstein, Koeltz Scientific Publications: 330 p.
Heywood V.H. (ed.) (1964) Pinaceae. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 1. Cambridge University Press, Cambridge: 29-35.
Lambinon J. (2005) Plantes introduites, naturalisées, invasives… : enrichissement de la biodiversité ou menaces pour la conservation de la nature. L’Erable 4(4): 2-9.
Page C.N. & Rushforth K.D. (1986) Picea. In: Walters S.M. & al. (eds.), The European Garden Flora, vol. 1: 95-98. Cambridge University Press, Cambridge.
Schmidt P.A. (1989) Beitrag zur Systematik und Evolution der Gattung Picea A. Dietr. Flora 182: 435-461.
Schmidt P.A. (1991) Beitrag zur Kenntnis der in Deutschland anbaufähigen Fichten (Gattung Picea A. Dietr.). Mitt. Deutsch. Dendrol. Ges. 80: 7-72.