Hembrain said:Maurice, the diagram and explanation are incredibly helpful. Thanks very much!
You are very welcom.
It undescores the importance of tracking growth in determining rebloom. So, if a distinct plant fan in a clump is smallish at the beginning of the growing season (or set back by transplanting or bareroot shipping) and blooms for the first time late in the season, it would be logged as (A).
In a clump, it might make the whole clump look like the cultivar is reblooming, but it's technically not.
Yes the whole clump will look like its reblooming and according to the AHS definition I would accept that the plant is reblooming.
But if that hardworking little fan and scape was the same-season increase from a blooming fan, as it would be with (B) or (C), it would be considered rebloom. Yes?
Yes, that would be rebloom.
I can look and see what often looks like one big fan with 2 scapes active. Technically it's 2 fans, (A) and (B). Right?
Yes.
Technically one growing point (shoot apical meristem) produces a number of leaves over one or more growing seasons and then becomes the scape and it is completely used up in producing the scape. So one fan of leaves produced by one growing point only ever has one scape.
When a daylily is growing continuously and it produces a scape then the fan of leaves produced by the first growing point A (which became the scape) and the fan of leaves that is produced by the replacement growing point B are indistinguishable so that it appears that one fan of leaves has produced two scapes.
Very rarely ("once in a blue moon") the switchover from the last leaf produced by the first growing point (A) and the first leaf produced by the replacement growing point (B) is not perfect and the last leaf of the A growing point is noticeably longer than the first leaf of the replacement growing point (B). To ever see this you would have to look at many fans of many cultivars many times during the growing season, even before any scapes appear and check leaf lengths when they are mature and have stopped growing longer.
I prefer to look at the growth and flowering of daylily crowns that are single fans and have a single shoot apical meristem or growing point. That means that they have a single growth axis. As long as the crown only has one growing point, even if that growing point becomes a scape (the fan flowers) then there is only one growth axis. That growth axis will rebloom if it produces more than one scape in a growing season.
If the crown produces two replacement growing points then it has two growth axes and the crown (or clump) now can rebloom even if each axis only produces one scape during the growing season as long as the flowering periods of the two scapes do not overlap. Yet neither growth axis has produced more than one scape in the growing season.
Discontinuous growth
If a single fan (growth axis) (growing point) crown grows discontinuously then that means it stops producing new leaves sometime during the growing season. If its growing point becomes a bud then when that bud sprouts it will be noticeable because the first few leaves it produces will never be as long as the last mature leaves of the previous growth. They will look like the first few leaves of a bud sprouting in the early spring. If that fan of leaves produces a scape in the same growing season as the previous fan then it is rather obvious that each "fan" of leaves produces one scape.
