278 ON THE EUROPEAN SPECIES OF FESTUCA. 



European species. If the growth of the axis of the bud be 

 ajiofjeotropic, the youug shoot continues to grow closely pressed to 

 the parent axis between it and the sheath of the leaf in the axil of 

 which it is produced; the author terms shoots thus produced 

 " innovationes hitrarar/inales.'" If the growth of the axis of the bud 

 be more or less diageotwpic, then its apex grows in a horizontal 

 direction and away from the parent axis, and it either pierces 

 through the sheath of the leaf in the axil of which it is produced, 

 or the bud has to wait until the sheath is decayed before it can 

 continue its growth. In either case the growth of the bud or shoot 

 continues outside the sheath, and the author terms buds which 

 have this mode of growth " innovationes extravaginales.'' 



This diageotropic growth continues for a longer or a shorter 

 period ; in the former case the shoot becomes a creeping rhizoma 

 (sobole), which ultimately curves upwards, and the after growth 

 becomes apogeotropic, as in F. ruhra-gemilna : in the latter case, 

 though the growth of the bud is at first diageotropic, yet after 

 piercing through the sheath the growth suddenly becomes apo- 

 geotropic, and the shoot is sharply bent at its base and continues 

 to grow parallel with and close to the mother axis ; this mode of 

 gi'owth takes place in F. rubra Y^v.fallax, and var. violacea. The 

 rhizoma in this case is densely caespitose, as in intravaginal growth. 

 Soboliferous growth must evidently always be extravaginal, yet 

 intravaginal growth (innovationes intravaginales) may present the 

 appearance of soboliferous growth, as in F. ovina when growing in 

 loose or sandy soil. When the direction of the shoot can no longer 

 be ascertained, as in herbarium specimens, such shoots as those 

 last described are often taken for soboles. Thus F. varia and 

 F. esJda have been described as often having a creeping rhizoma, 

 though these two species are intravaginal. The author terms the 

 rhizoma with this peculiar growth — rhizoma pseudo-repens, and he 

 has noticed it in F. ovina var. glauca, var. vaginata ; F. varia, 

 F. elegans, and F. sijlvatica. Glyceria maritima when deeply 

 covered with mud exhibits a similar growth, and has been 

 described, erroneously, as having a creeping rhizoma. 



In living specimens the character of the innovation is easily 

 observed. The first leaf of the innovation of intravaginales is long 

 and linear, as long as the sheath of the following leaf — Ex. F. ovina, 

 F. varia. The first leaf of intravaginales is short, roundish or 

 ovate, and much shorter than the following leaf-sheath — Ex. F. 

 sylvatica, F. laxa. The succeeding leaves of intravaginales are 

 perfect, and furnished with blades. The succeeding leaves of 

 extravaginales are 1-3, or in F. sylvatica 4-5 in number, and are 

 bract-like, without blades. There are only two instances, among 

 the Euroj^ean species of Festuca, of geotroj)ic growth, viz., F. spa- 

 dicea and F. ccendrscens. 



The author considers the root-fibres of little value in the 

 discrimination of species. 



Characters drawn from the form of the stem, whether angular 

 or round, &c., cannot be depended on. 



Characters drawn from the innovation leaves are more valuable 



