62 DIMORPHIC BRANCHES IN TROPICAL CROP PLANTS. 



matical sense only one bud could be axillary. No subsequent adventi- 

 tious bud could be trul}^ axillar3^ Yet to apply such a distinction to 

 coffee would reduce it almost to an absurdity. Some of the fruit buds 

 might be reckoned as axillary, but others closely adjacent would 

 have to be considered as extra-axillary. The leafy branches which 

 can be forced from these same axils by pruning would be axillary if 

 they came out first, or extra-axillary if they followed a crop of 

 flowers, a purely artificial distinction. Instead of attempting to 

 establish too sharp a contrast between axillary and extra-axillary it 

 would be better to admit a third and intermediate positional category 

 of adaxillary branches, for those that stand close to the axil, as dis- 

 tinguished from extra-axillary branches that are distinctly separated 

 from the axil. 



If many buds arise simultaneously or successively from the axillary 

 position, or as near to it as they can be placed, they might be termed 

 coaxillary. The inflorescence branches of coffee could be described afs 

 coaxillary, and probably those of Cuscuta." 



In describing the functions of branches, distinctions are also to be 

 observed. Some branches are completely vegetative and produce no 

 floAvers or inflorescences; some are completely reproductive, in the 

 sense that thev bear only floral buds. Between the two extremes a 

 great multiplicity of intervening stages exists. Sometimes branches 

 which normally bear fruit can be sterilized and rendered purely 

 vegetative. In some j)lants all branches have equal vegetative poten- 

 tialities; in others, as in coffee, cotton, and Castilla, the upright main 

 stems are different from the lateral fruiting branches. In some 

 plants these lateral branches can, in case of accident, become substi- 

 tutes for upright stems ; in others, they can furnish buds from which 

 upi'ight stems can arise ; in still others, the lateral branches are with- 

 out the 2:>ower to replace the main steam. 



The existence of two or more buds in or about the axil of a leaf is 

 known, of course, in many jDlants and has been recognized by writers 

 on plant morphology, but definite specializations of positions and 

 functions have not received the attention required b}^ the agricultural 

 importance of such facts. As long as no difference of function has to 

 be considered, additional buds can be considered as mere substitutes 

 or accessories of the true axillary bud. Thus Pax ^ recognizes what 



° Dr. C. E. Bessey, in ;i paper on the adventitious inflorescence of Cuscuta 

 glomerata, stated that the examination of young plants shows that the in- 

 florescence is developed from numerous crowded adventitious buds and not by 

 the repeated branching of axillary flowering branches, as commonly stated. 

 Science, vol. 4, 1884, p. 342. 



^ Pax, F. Allgemeiue Morphologie des Pflauzen, p. 36. 

 198 



