L. Lőkös szerk.: Studia Botanica Hungarica 27-28. 1996-97 (Budapest, 1978)

Csontos, Péter: Seed bank behaviour of Verbascum L. species

England (WARR et al. 1994). This species was also reported by ARTIGAS and BOERNER (1989) from the seed bank of pine stands in Ohio. In two cases mulleins were involved in long-term experiments with artificially buried seeds. DUVEL buried Verbascum thapsus in a longevity test and found the seeds viable throughout the 39 years long study (TOOLE and BROWN 1946). In the W. J. BEAL's experiment Verbascum blattaria L. and V. thapsus seeds remained viable after one hundred years of burial (KIVILAAN and BANDURSKI 1981). The facts listed above might induce to ask how much the strategy of forming persistent soil seed bank is common in the genus. To support the decision by new data, seed bank studies of two mulleins {Verbascum austriacum and V. lychnitis), not yet investigated, was decided. MATERIALS AND METHODS Brief characterization of the investigated species are given below (based on SOÓ 1968, MEUSEL etal. 1978 and HORVÁTH etal. 1995): Verbascum austriacum Schott - Area includes south-east Europe from Czech Republic to Bulgaria. Native to Hungary, often found in mountainous and hilly regions, rare on the lowlands. Plant height: 0.5-1.0 m; RAUNKIAER's lifeform: TH-H; flowering time: June-August; cytotaxonomy: polyploid, 2n = 32. Prefers xerotherm oak woodlands (associations of Quercetea pubescenti-petraeae) but also found in some drier or more humid vegetation types. Moisture requirement in accordance with semi-dry habitats. (Syn.: V. chaixii var. austriacum Franch.) Verbascum lychnitis L. - Area ranges from the German Lowland to south Italy and from France to the river Volga. Native to Hungary, apart from high mountains and closed canopy forests it is widespread in the whole country. Plant height: 1.0-1.5 m; RAUNKIAER's life-form: TH; flowering time: May-August; cytotaxonomy: polyploid, 2n = 32. Prefers xerotherm grasslands (associations of Festuco-Brometea) sometimes occurs in xerotherm woodlands. Often found in habitats with long dry period. Seeds of the two species were collected on 12 September, 1992 at Pilisszentlászló and on 24 October, 1992 at Csévharaszt, respectively. For each species one hundred seed units were mixed with sterilized sand and filled into flower pots then buried at 60 cm depth, in ten replicates, in Autumn 1992. This burial depth was intended to induce enforced dormancy of the seeds (FENNER 1985). Following exhumations (21.04.1993, 30.04.1994, 28.03.1995 and 25.03.1996) seeds were spread out on the surface of soil kept in plastic trays then exposed to light and moisture (26.04.1993, 03.05.1994,