Drypidetalia

Order Drypidetalia spinosae Quézel 1964

Alliance Geranio—Pseudofumarion albae Trakić et al. all. nov. hoc loco

Holotypus: Table 3, rel. 18

Characteristic species: Pseudofumaria alba , Geranium robertianum , Vincetoxicum hirundinaria , Clematis vitalba .

Diagnosis: The alliance Geranio—Pseudofumarion albae occurs in the zone of inner Dinarides, following its NW-SE direction, in altitudinal range from 200 to 1800 m a.s.l.. It requires high air humidity associated either with canyon's microclimate or high precipitation rate on the macroclimate scale. Herein described alliance characterizes high vegetation coverage due to favourable edaphic conditions (high humus content). Frequently occuring species: Moehringia muscosa , Saxifraga rotundifolia , Lactuca muralis , Senecio squalidus subsp. rupestris , Geranium lucidum and Urtica dioica indicate afore described ecological preferences of the alliance. In the subalpine belt of SE Dinarides, the alliance is characterized by the occurence of Rumex scutatus and Drypis spinosa .

It should be also noted that additional taxonomic research would be required in order to make a clear distinction between the subspecies in question. According to the Euro+Med Plantbase (2006-) P. a. subsp. leiosperma occurs in Bosnia and Herzegovina, Serbia, Montenegro, Albania, North Macedonia and Greece, whereas P. a. subsp. acaulis is limited to Bosnia and Herzegovina and Croatia ( Lidén 2011). One might also expect the occurrence of hybrids in the overlapping area, that is in Bosnia and Herzegovina which is additionaly favoured by extreme conditions in screes. Fukarek (1960) has already pointed out dubious differentiation of considered subspecies, suggesting that they might be ecotypes occurring in different habitats. Accordingly, ecological optimum for P. a. subsp. leiosperma is to be found in the subalpine belt, whereas P. a. subsp. acaulis prefers lower altitudes ( Beck 1917).

Based on our findings, we propose the syntaxonomical scheme for screes dominated by P. alba occurring in open habitats, with phanerophytes as accompanying species only. The associations containing different subspecies of P. alba are treated separately.