38 



BUDS ON LEAVES. 



leno-th from the base. It there terminates in a bud, or, if it divides, in several 

 buds, and inasmuch as these ai-e flo^Yer-buds, it may be looked upon as a tlower- 

 stalk. These buds cannot therefore be said to be epipliyllous, i.e. to spring direct 

 from the tissue of a i'oliage-leaf. In reality each is borne upon a structure of 

 the nature of a stem, only the peduncle, stalk, or axis has pai-tially coalesced with 

 the midrib of a leaf. Willdenow, who wtis tlie first to desci-ibe it, named the plant, 

 represented in fig. 198, the Butchers-broom Helwingia {Hehvingia rusdflora), 



,i^.Jmiirif.*-,i., , 



Vi'^. V!i%.~ Helwingia rxtscijiora, with tlowers sontoil upon the foliago-leavoB, 



because the floral buds here as in the Butcher's -broom (Rust^as) were borne by 

 foliaceous structures (c/. vol. i. p. 333). The two cases are, however, essentially 

 different. The green leaf -like structures in the Butchor's-broom, which carry flonxl 

 buds upon their upper surfaces, are not leaves at all, but leaf -like shoots, that is 

 to say axes, and the buds upon them ai-e, therefore, not epiphyllous but cauline. 

 The same statement applies, of course, to other plants with flat, expanded shoots, 

 a few representatives of which arc shown in the illustration of p. 335 of the fii"st 

 volume, and in this category must be included Ferns also, if we look upon their 

 fronds as phylloclades, and not as foliage-leaves. It would be quite out of place 

 here to enter into the question of the nature of fern-fronds, or to set forth the 

 reasons why they must be considered as phylloclades. The proof cannot be 



