Thesium ebracteatum Hayne

Roleček, Jan, Novák, Jan & Bobek, Přemysl, 2025, Thesium ebracteatum (Santalaceae) rediscovered in Romania: ecological and biogeographical context, Biodiversity Data Journal 13, pp. e 172455-e 172455 : e172455-

Thesium ebracteatum Hayne

Distribution

Thesium ebracteatum was recorded on 14 June 2025 near Bălcăuți ( Suceava Region), at the foot of Dealul Stejenii Hill, in a transitional zone between species-rich forest-steppe grassland and intermittently wet Molinion meadow (Fig. 2 ). Approximately 100 individuals were found here. The observed plants were characterised by a tuft of sterile leaves at the top of the stem, the absence of bracteoles, shortly pedicellate flowers and short perianth segments that, in fruit, were, at most, as long as the nutlet (Fig. 3 ). Thesium rostratum , a similar Central European species reported as insufficiently known from Romania ( Oltean et al. 1994), is differentiated by its sessile flowers, a tubular rather than campanulate perianth that is up to three times as long as the nutlet in fruit and a rhizome lacking stolons ( Tutin 1993). A herbarium voucher specimen from the newly-discovered population of T. ebracteatum has been deposited in the Herbarium of Masaryk University, Brno ( BRNU).

Notes

Vegetation

A phytosociological relevé of local vegetation with T. ebracteatum was recorded the following day.

Relevé 1: Romania, Suceava Region, Bălcăuți, foot of the Dealul Stejenii Hill, forest-steppe grassland transitioning to intermittently wet Molinion meadow, latitude 47°51'25.6"N, longitude 26°03'19.8"E (WGS- 84), altitude 375 m a. s. l., plot size 16 m 2, slope inclination 5 °, slope aspect 330 °, cover of herb layer 65 %. Date: 15 May 2025. Author: J. Roleček.

Inula salicina 3, Carex montana 2 b, Potentilla alba 2 a, Serratula tinctoria 2 a, Filipendula vulgaris 1, Molinia arundinacea 1, Peucedanum cervaria 1, Anemone nemorosa +, Brachypodium pinnatum +, Campanula glomerata +, Campanula persicifolia +, Cirsium pannonicum +, Clematis recta +, Colchicum autumnale +, Crepis praemorsa +, Euphorbia angulata +, Festuca rupicola +, Festuca valesiaca +, Galium boreale +, Galium verum +, Geranium sanguineum +, Inula hirta +, Iris graminea +, Knautia arvensis agg. +, Lathyrus pannonicus subsp. collinus +, Lathyrus pratensis +, Plantago media +, Potentilla erecta +, Primula veris +, Prunella grandiflora +, Pulmonaria mollis agg. +, Ranunculus auricomus coll. +, Ranunculus polyanthemos +, Salvia pratensis +, Silene nutans +, Stachys officinalis +, Thesium ebracteatum +, Trollius europaeus +, Veratrum lobelianum +, Veratrum nigrum +, Vicia cracca agg. +, Viola hirta +, Centaurea jacea r, Dianthus superbus r, Galium album r, Muscari botryoides r, Phragmites australis r, Poa angustifolia r, Sanguisorba officinalis r, Succisa pratensis r, Tanacetum corymbosum r, Taraxacum sect. Taraxacum r, Thalictrum aquilegiifolium r, Trifolium montanum r, Valeriana stolonifera subsp. angustifolia r, Veronica chamaedrys agg. r, Viola canina subsp. ruppii r.

Figures

Figure 2. An overall view of the Thesium ebracteatum site. The red arrow indicates the location of the population. Fânațele seculare de la Calafindești Nature Reserve is shown as green slopes on the right side of the image, just east of the locality. The horizon is dominated by the village of Calafindești.

Figure 3. Thesium ebracteatum at the newly-found locality. The species is characterised by a tuft of sterile leaves at the top of the stem, the absence of bracteoles (only a single bract subtending each flower is present), shortly pedicellate flowers and short perianth segments that, in fruit, are, at most, as long as the nutlet.