PROLIFERATION OF SPIKELETS IN BRITISH GRASSES 



45 



Hackel (1882, 88) put all viviparous plants into a subvariety thus : F. ovina subsp. 

 eu-ovina var. supina subvar. vivipara. In 1925 Howarth revised the sheep's fescues in 

 Britain and found viviparous specimens of F. capillata Lam. (i.e. F. tenuifolia Sibth.), 

 F. ovina L. sensu stricto, F. supina Schur and F. longifolia Thuill. (he raised Hackel's 

 subspecies to species). He suggested that perhaps only specimens of F. supina were 

 constant in their vivipary. 



Virtually the only vegetative character that divides F. supina from F. ovina is that 

 the radical sheaths are entire over their lower third in the former, but completely split 

 in F. ovina. Better subepidermal sclerenchyma development was found by Howarth 

 in F. supina. Extensive cultivation of seminiferous and viviparous specimens convinced 

 Turesson (1926-7) that it was impossible to group all constant viviparous forms under 

 one head and the distinction between F. supina and F. ovina had no value. Subsequent 

 works have not revived F. supina as an important taxon. 



Tutin (1952, 1426) gives specific rank to four segregates of F. ovina agg., namely : F. 

 ovina L. (of which two subspecies, subsp. ovina and subsp. tenuifolia (Sibth.) Tutin are 

 admitted), F. vivipara (L.) Sm., F. trachyphylla (Hack.) Krajina [non Hack.] (i.e. F. longi- 

 folia Thuill.) and F. glauca Lam. This is satisfactory except for the statement that 

 viviparous plants resemble vegetatively F. ovina subsp. tenuifolia, which is the F. capillata 

 of Howarth. 



The characters of the segregates are tabulated in Table 1. Fully viviparous fescues 

 must be determined by vegetative characters. Robustness of the laminae and length of 

 inflorescence parts increases from subsp. tenuifolia via subsp. ovina to F. trachyphylla. 



Table 1 



Characters to distinguish Festuca ovina subsp. tenuifolia, F. ovina subsp. ovina and F. trachyphylla 





tenuifolia 



ovina 



trachyphylla 



Width of the leaf-blade in miiUmetres 



0-3-0-5 



0-3-0-7 



0-6-M 



Length of leaf proportional to culm height 



Long, ^ culm 

 or more 



Short 





Auricles 



Markedly lobed 



Rounded 





Length of spikelet mm 



3-6 



4-8 



6-10 



Length of lemma mm 



2-5-4 



3-5 



4-5-5 



Points of lemmae 



Mucronate 



Awned 

 Awn - 1 mm 



Awned 

 Awn - 3 mm 



Sometimes hairy leaf-sheaths and scabrid rhachides are given as additional F. trachypliylla characters, but 

 they are neither constant for F. trachyphylla nor always absent in the F. ovina subspecies. Leaf length and 

 auricle characters for F. trachyphylla are not given, but the present author finds that they approach the subsp. 

 ovina. 



4.2. Observations 



Thirty-eight specimens of F. vivipara (both partly and fully viviparous) were collected 

 in different parts of the British Isles. Twenty-nine have survived transfer to London, 

 twenty-two have since produced culms. In addition twenty-seven other living specimens, 

 of which twenty-four survived, were assembled; some were gifts from other collections. 

 Seminiferous fescues have also been grown. 



