Panarctic Flora

420112-13 The Stellaria hebecalyx aggregate S. hebecalyx, S. ponojensis

Geography: European (N).

Notes: Two species may be involved in what generally has been considered as Stellaria hebecalyx (e.g., Matzenko 1971; Jalas and Suominen 1983; Chater and Heywood 1993). Stellaria hebecalyx s. str. is temperate to boreal and reaches the Arctic as native in northeastern European Russia. The native plants from the arctic Murman coast differ appreciably from S. hebecalyx s. str. and have been described as S. ponojensis. Stellaria ponojensis should be evaluated for rank as a species apart due to its comparatively broad and very glaucous leaves, semi-prostrate growth, cymes with few to one flowers, and differently shaped sepals. The first description of S. ponojensis (Arrhenius 1888: 190) was insufficient but was later validated by an unambiguous diagnosis and type designation (Arrhenius 1889). This species or group is largely unexplored and in need of revision but we have provisionally accepted S. ponojensis.

Both plants are present in the Arctic in both Norway and Russia. In Norway, S. ponojensis occurs as assumedly native in one locality in sand-dune slacks, S. hebecalyx s. str. in another locality as an assumed adventive but established perhaps for 200 years or more (Elven 1985; Elven et al. in prep.).