Morphological characters that group members of this subgenus are: lemma rounded; auricles (Fig. 2-7) present, falcate (or sometimes a spreading, undulating flange); ovary glabrous; new shoots extravaginal; lemma awns present or absent. This subgenus can be equated with Festuca section Bovinae.
The most famous member of the broad-leaved fescues is 6x Lolium arundinaceum (hexaploid tall fescue, formerly known as Festuca arundinacea), well known for its excellent herbage yield and persistence, as well as enhanced resistance to many grass pathogens (see Chapter 8, Chapter 9, and Chapter 10). Tall fescue is popular where it was introduced, especially in North America, but not considered good forage in most of its native European habitat. The evolution of tall fescue, and distinction of northern and southern ecotypes, is discussed further below (see Evolutionary Origins of Hexaploid Tall Fescue section in this chapter).
Hexaploid (6x) tall fescue (at least the northern type) is related intimately to two European broad-leaved fescues: the diploid (2x) L. pratense (= F. pratensis, meadow fescue) and the tetraploid (4x) L. arundinaceum [= F. arundinacea subsp. fenas (Lag.) Arcang. = F. arundinacea var. glaucescens Boiss., often but invalidly called Festuca glaucescens]. The North African species F. scariosa (Lag.) Asch. & Graebn. (2x) and Festuca mairei St.-Yves (4x) also are thought to be important in the evolution of subgenus Schedonorus. These two geographical groups of grasses share a fascinating relationship with each other, where some species or varieties have hybridized with others, resulting in the formation of new species. The resulting polyploid series is most evident in the Atlas Mountains of North Africa, and its members have been classified as varieties or subspecies of Festuca arundinacea, particularly F. arundinacea subsp. atlantigena (St.-Yves) Auquier (8x), F. arundinacea subsp. cirtensis (St-Yves) J. Gamisans, and F. arundinacea var. letourneuxiana (St.-Yves) Torrecilla & Catalán (10x). In this chapter, we shall refer to the F. arundinacea subspecies and varieties simply as 4x, 6x, 8x, and 10x L. arundinaceum. Current ideas about the evolution of this group are discussed more fully in the section Evolutionary Origins and Geographic Distribution of Species in Subgenus Schedonorus.
Fig. 2-7. Auricles of hexaploid tall fescue (6x L. arundinaceum), a morphological character that groups subgenus Schedonorus grasses together.
|<--Previous||Back to Top||Next-->|