Common Names

Taxonomic notes

Like the other two widespread European pines, P. sylvestris and P. mugo, this species has received an excessive number of described names, a consequence of very narrow subspecific and varietal concepts applied notably in France and parts of Eastern Europe. In some areas virtually every small clump of trees has been given its own scientific name, many of them invalid under the International Code of Botanical Nomenclature, giving P. nigra the appearance of an extremely variable species. Although it is variable, it is not markedly so compared to other widely distributed conifers worldwide; across its entire range, it shows a level of genetic diversity similar to many other Pinus species (11). The eight or more subspecific names accepted by Vidakovic (12) and some others is not reflected in usage among other conifers with similar levels of variability.

The most prominant variation in P. nigra occurs between trees from the eastern and western halves of its range, which differ strongly in foliage (1, 3, 5, 6, 7, 12) and genetic structure (11) and have been assigned to different subspecies. The (typical) eastern subspecies, found in Austria, the Balkans, Greece, Turkey, Cyprus and the Crimea, has stout, rigid needles usually 1.5-2.0 mm thick, which persist for 4-7 years on the tree. Their needle anatomy shows 3-6 layers of hypodermal cells with strongly thickened cell walls. The western (salzmannii) subspecies, from Italy, S France, Corsica, Spain and the Atlas Mountains of NW Africa, has slender, flexible needles 0.8-1.5 mm thick which persist for 2-4 years on the tree. In needle anatomy they have only 1-2 layers of hypodermal cells with thin cell walls.

The difference in foliar morphology between the subspecies reflects a more severe winter climate in the eastern populations. Winter temperature minima are markedly lower in this more continental climate, with absolute minima sometimes falling below -30°C in most of the eastern subspecies' range. Minima in the western subspecies' range rarely fall as low as -20°C. Forestry trials in cold areas of the USA (8, 13) have consistently found eastern origins to be significantly more cold-tolerant than western origins.

The two subspecies are separated by a large range gap across the Adriatic Sea and the Po valley of Northern Italy, leaving unoccupied over 600 km of apparently suitable habitat in the southern Alps. Given the range disjunction and the differences in morphology and adaptation, the eastern and western groups meet accepted criteria for the rank of subspecies in conifers (e.g. 2) and are here so treated. The eastern populations form the typical subspecies, subsp. nigra, with the western populations classified as subsp. salzmannii (Dunal) Franco (3, 4).

Within both subspecies, further minor geographic variation occurs, mainly in cone size and colour, needle length and bark colour, which may be treated at varietal level. There is considerable overlap and clinal gradation in these characters (12), and the populations are only reliably distinguishable on the basis of means compiled from the measurement of many trees. This is confirmed by isoenzyme and allozyme studies (10, 11), which show high within-population genetic diversity accounting for 94% of the diversity (11), with most alleles distributed across the range of each subspecies. Individual trees are therefore not always assignable to a variety without prior knowledge of their origin. Each of the subspecies is divided here into three varieties.

Subsp. nigra J.F. Arnold (this page), the thick-leaved eastern subspecies, comprises:

• var. nigra J.F. Arnold [Austrian pine; syn. var. austriaca Höss; var. gocensis Georgev.; var. banatica Georgescu; var. illyrica Vidakovic; ssp. gocensis (Georgev.) Vidakovic; ssp. dalmatica (Visiani) Franco; ssp. croatica Lovric; P. nigricans Host; P. dalmatica Visiani].
• var. caramanica (Loudon) Rehder [Turkish black pine; syn. P. taurica (Loudon) Steud.; P. fenzlii Antoine & Kotschy ex Carrière].
• var. pallasiana (Lambert) Asch. & Graebn. [Crimean pine; syn. P. pontica K. Koch].

Description

The varieties may be distinguished as follows:

var. nigra: leaves 6-14 cm, cones dull grey-buff, 4.5-9 cm, bark on old trees grey.

var. caramanica: leaves 8-16 cm, cones bright yellow-buff, 5-10 cm, bark on old trees orange-pinkish.

var. pallasiana: leaves 10-18 cm, cones dull grey-buff, 7-12 cm, bark on old trees orange-pinkish.

Range

Var. nigra in Austria, Romania, Slovenia, Croatia, Yugoslavia, Macedonia, Albania and Bulgaria, at low to moderate altitudes (200-1200 m), in southeast European continental climates with some summer rainfall; intergrading with var. caramanica in the south.

Var. caramanica in Greece, Turkey (southern or possibly all), and Cyprus, at moderate to high altitudes (800-2000 m) in strictly Mediterranean climates with no summer rainfall.

Var. pallasiana in the Crimea and the Black Sea coast of the Caucasus, at low to moderate altitudes (200-1200 m), with some summer rainfall; northern Turkish populations may belong here.

Big Tree

Oldest

Dendrochronology

Ethnobotany

Observations

Remarks

Citations

This page is from the Gymnosperm Database
URL: http://www.geocities.com/~earlecj/pi/pin/nigra.htm
Edited by Christopher J. Earle
E-mail:earlecj@earthlink.com
Last modified on 25-Mar-1999