Tall Fescue Online Monograph

This group of grasses, commonly referred to as the fescues, is utilized worldwide as forage and turf. Together with the genus Lolium (discussed below), these grasses form the backbone of pastoral agriculture in cool and temperate regions of the world (see Chapter 3).

Morphological characteristics that serve to group the genus Festuca together are: perennial growth habit; leaf blades mostly rolled or conduplicate, but sometimes flat; inflorescence (Fig. 2-5); an open or contracted panicle; two- to several-flowered spikelets; upper glume usually membranous to thinly coriaceous, rounded on back at least toward base, lemma acute to awned, with the awn terminal or rarely subterminal; floret callus and rachilla glabrous; three stamens; ovary apex sometimes hairy; hilium linear, rarely oblong.

Hackel (cited in Jauhar, 1993) originally classified grasses in genus Festuca into six sections on the basis of leaf morphology and ovary structure: Bovinae, Montanae, Subbulbosae, Scariosae, Ovinae, and Variae. Sections Scariosae, Subbulbosae, and Montanae are believed to be relatively unspecialized and may be more primitive (Stebbins, 1986). Two divergent evolutionary trends emerge from these unspecialized sections: one leading to section Bovinae (of which hexaploid tall fescue is a member, Fig. 2-6) and the other leading to sections Ovinae and Variae. Of these sections, two are of primary importance here. Section Bovinae (= subg. Schedonorus) contains the broad-leaved fescues and section Ovinae (= subg. Festuca) contains the fine-leaved fescues.

Although these two subgenera (Festuca and Schedonorus) share many morphological characters, evidence mounting from hybridization studies and molecular data suggests that there is considerable evolutionary divergence between them (see Realignment of Schedonorus with Lolium section in this chapter). As a consequence, Darbyshire (1993) proposed that the broad-leaved species in Festuca subg. Schedonorus be reclassified to Lolium subg. Schedonorus. This has important consequences for grass taxonomy, as subgenus Schedonorus contains tall fescue, meadow fescue [Lolium pratense (Huds.) Darbysh. = Festuca pratensis Huds.], and other agronomically important grasses. For the sake of clarity and continuity, we will adopt the genus name Lolium when referring to grasses of this group, but they are discussed here with genus Festuca, where they have traditionally been classified (see Realignment of Schedonorus with Lolium section in this chapter).