Notes on Festuca ovina

F. ovina L. typical (on the left) and a morph with thick leaves (on the right) (Finland, Lohja, Outamo, 2002). – Image: Harri Harmaja (scanned from dried specimens). – The right-hand plant, according to my observations, differs from typical F. ovina (Poaceae) by (i) the slightly stouter habit and stiffer leaves, (ii) the broader leaves of the sterile regeneration shoots (0.5-0.9 mm vs. 0.3-0.5 mm when dry), (iii) the slightly blue-green (vs. more grass-green) tinge of the leaves, (iv) the spikelets which generally have more flowers, and (v) the awn of the lemma which tends to be longer (1.0-1.6 vs. 0.4-1.5 mm). Moreover, Dr. Rense Haveman (Wageningen, The Netherlands) and Dr. Petr Šmarda (Brno, Czech Republic) – who both kindly examined material sent by me – found that the leaves of the right-hand plant have more veins (about 7-11) than typical F. ovina which has 5(-7) veins.
    The broad-leaved plant is definitely indigenous, occurring scattered among typical F. ovina in a sunny SW slope of undisturbed, siliceous, mesotrophic rock outcrops, with e. g. Arctostaphylos uva-ursi, Campanula rotundifolia (indigenous race), Solidago virgaurea (narrow-leaved race) and Silene rupestris.
    The features of this more robust Finnish fescue remind of those of two tetraploid species of Central Europe: F. guestphalica Boenn. ex Rchb. (F. ovina var. firmula (Hack.) Hegi) and F. heteropachys (St.-Yves) Patzke ex Auquier. Dr. Šmarda measured by flow cytometry the DNA content of the nuclei of both Lohja plants treated here. Both morphs were found to be at the diploid level (2n = 14) which is the character of F. ovina s. str. Consequently, the right-hand plant in the image above is either an unknown taxon or a mere modification.