EDIBLE CANNA IN WAIMEA DISTRICT OF HAWAII 
15 
To determine the relative desirability of the different types of root- 
stocks for seed purposes, a portion of an 18-month-old field of canna 
was dug and the rootstocks were divided into six groups having the 
following characteristics : 
Subsurface type (fig. 7). — Rootstocks of the subsurface type are 
small and cylindrical to tapering and constitute the first two genera- 
tions. They exist in a dormant state in a hill 12 months old and their 
stems are dead. The rootstock grows beneath the surface of the soil 
in contrast with the surface types. The subsurface type has short 
internodes and may bear buds at practically every node from base 
to apex. As many as 10 have been observed on a single rootstock, 
although 2 and 3 are the rule. The buds, which are usually small, 
remain dormant until the newer growth of the hill is checked. 
Immature rootstocks, surface type (figs. 8 and 9). — This type grows 
largely above ground and is oval shaped. The buds have large basal 
Fig. 9.— Base of hill of canna 5 months old 
attachments to the parent and appear only near the apex of the root- 
stock. Usually two buds are seen, but occasionally a third appears 
which ordinarily does not develop. On some rootstocks of this 
group one bud has already reached the rootstock stage and has been 
removed, whereas on the youngest members only one bud has made 
its appearance. (Fig. 10.) The stalks of this group are immature and 
sometimes entirely undeveloped spikes. The group is further sub- 
divided into (1) large rootstocks constituting the most vigorous and 
newest growth of the hill; and (2) small rootstocks constituting the 
secondary growth. (Fig. 11, A and B.) The secondary growth appears 
during the later stages of growth of the hill, or after the vigorous 
growth has been stopped by adverse weather conditions. 
Attached spike. — This type is like the immature surface type except 
that one or both of the buds have developed into spikes which are 
not of sufficient size to be called rootstocks. For seed purposes the 
spike is left attached to the parent. 
