vu] RACHILLA, “WEB,” ETC, 131 
palea as tapering into a sharp point (awn-point). It must 
be admitted that the distinction is somewhat artificial, but 
it has its advantages in practice. 
Fig. 50. Bromus sterilis. a, ‘‘seed,” Fig. 51. Festuca sylvatica. a, 
nat. size; bande, ditto, x about ‘‘ seed,” nat. size; b and ce, 
2. Nobbe. Cf. Figs. 80 and 81. ditto, x 8. Nobbe. Cf. Fig. 78. 
The rachilla (Fig. 41), when present, often affords good 
characters, and in a few cases is relied on for the dis- 
tinction of “seeds” otherwise much alike—e.g. Loliwm 
perenne and Festuca elatior; and similarly with the 
presence or absence of hairs (Digraphis, Arundo, &c.) 
or “web” (Poa) at the base of the “seed.” (Figs. 55, 69.) 
On germination the primary root of the embryo 
usually emerges and at once plunges into the soil, but 
soon ceases to grow, and the secondary roots (and sub- 
sequently adventitious rootlets from the lower internodes) 
soon give the peculiar fibrous character so well known in 
grass-roots. 
9—2 
