Notes on Agrostis capillaris

Agrostis capillaris L. (Poaceae) with completely or predominantly "viviparous" inflorescences (Finland, Lohja, Vanhakylä, 2003). – Image: Harri Harmaja (scanned from fresh panicles). – These striking plants result from an overgrowth of the lemma of a spikelet so true viviparous bulbils are thus not formed. In the summer of 2003, such plants were observable in places in South Finland. It is not impossible that the somewhat exceptional weather conditions of the growing season of 2002 and early 2003 might have provoked this phenomenon; e.g., plants of A. capillaris developed luxurious sterile shoots in the autumn of 2002. The phenomenon appears to have no taxonomic significance (Widén, K.-G. 1971: The genus Agrostis L. in eastern Fennoscandia. Taxonomy and distribution. – Flora Fennica 5: 1-209.). – A nematode species sometimes causes deformations of Agrostis spikelets, and the infrequent parasitic smut fungus Tilletia sphaerococca (Rabenh.) A.Fisch. v. Waldh. (also found by me in Lohja) dwells the insides of the spikelets of A. capillaris and causes the plants to be dwarfed