Preliminary Course
Botany. Architectural Analysis
Axis typology.
Sexuality and development
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Determinate and indeterminate growth
- Lateral flowering does not change the axis development strategy.
- Apical flowering stops axis development.
In this case, axis development is only possible from axillary buds.
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When a terminal meristem can produce (phytomers) all the life span of the plant, its bearing axis has indeterminate growth
(a theoretical viewpoint).
Whereas, when meristem production is limited in time, ending with a flower differentiation or a tendril or a spine or by death of apical meristem, its bearing axis shows determinate growth.
The sexuality position therefore impacts on plant development.
Sexuality position and axis development (Photos D. Barthélémy, CIRAD)
Left: lateral sexuality and indeterminate growth (Cocos nucifera)
Right: terminal sexuality and determinate growth (Isertia sp)
Monopodial and sympodial development
Plants with monopodial development grow upward from a single meristem. They add leaves to the apex each year and the stem grows longer accordingly.
Plants with sympodial development have a specialized lateral growth pattern in which the apical meristem is terminated.
The apical meristem can either be consumed to make an inflorescence or other determinate structure, or it can be aborted.
Growth is continued by a lateral meristem, which repeats the process. The result is that the stem, which may appear to be continuous, is in fact derived from multiple meristems, rather than a monopodial plant whose stems derive from one meristem only.
Monopodial and sympodial development (Photos D. Barthélémy, CIRAD)
Left: Monopodial and indeterminate growth (Albies alba)
Centre: Sympodial development, with terminal sexuality and determinate growth (Plumeria sp)
Right: Sympodial development, with terminal sexuality and determinate growth building a single stem (Ailanthus altissima )