Sympodium

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Related to sympodial: monopodial

sympodium

[sim′pōd·ē·əm]
(botany)
A branching system in trees in which the main axis is composed of successive secondary branches, each representing the dominant fork of a dichotomy.

Sympodium

 

the axial organ of a plant (root or stem), consisting of successive secondary axes and arising as a result of topping during growth and branching.

With dichotomous branching, which characterizes lower plants and a number of higher sporebearing plants (for example club mosses), the sympodium arises as a result of the more intensive growth of one of the bifurcated branches and the sideward displacement of the branch at each of the repeated stages of branching. In lateral branching, which is a feature of most higher plants (including all flowering plants), the sympodium forms as a result of the cessation of top growth of the root or the shoot; a lateral root or shoot arises that generally grows in the same direction as the displaced element. Curtailment of activity at the tip of the meristem can be caused by death resulting from external damage (desiccation, freezing, cutting), by the formation of an apical flower or inflorescence that includes the entire tip of the meristem, or by the deflection of the main axis away from the original growth direction.

The trunks and large branches of most hardwood trees and shrubs are typical sympodia, as are the rhizomes of most perennial herbs. Topping occurs in these organs many times, sometimes as often as once a year. Inflorescences that are formed according to the same principle as sympodia are called cymose. The sympodium is most clearly seen in monochasia.

T. I. SEREBRIAKOVA

References in periodicals archive ?
While number of sympodial and monopodial branches were counted on 10 randomly selected plants from each replication.
Maximum SCA was observed in the trait sympodial branches per plant, with the hybrid CIM-497 x NIAB-999 (1.
Leaf blade broadly ovate or oblong-lanceolate to elliptic, 6-19 cm long; base symmetrical in sympodial leaves, obtuse to rounded, sometimes cordate in monopodial leaves; palmately veined with 3-7 veins; non ciliate and glabrous on both surfaces.
The variances due to general combining ability (GCA) and specific combining ability (SCA) presented in Table 2 were also significant for bolls/plant, sympodial branches/ plant, fibre length, plant height and seed cotton yield/ plant and lint% except that GCA was non-significant for boll weight and seed index whereas, SCA was non-significant for boll weight, seed index and lint%.
The abortion of the main shoot and subsequent sympodial growth in the adult plant was registered by Koutnik (1984) as a unusual synapomorphy.
The lines were found to be statistically different at a significant level from the control in Number of Sympodial Branches per Plant, Plant Height and Ginning Outturn Percentage (GOT).
As mentioned earlier, an increase in fiber strength is coupled with a high percentage of position 1 bolls on the sympodial branch under moisture deficit (Pettigrew, 1995).
Sympodial angiosperms with adventitious roots inevitably have patterns of vessel evolution different from those seen in monopodial woody angiosperms with taproots.
Data collection: Five randomly selected plants from each experimental unit were tagged and measured for different yield components like number of sympodial branches plant -1, number of mature boll plant-1 and seed cotton yield kg ha-1.
Clusters of intercalary or terminal conidia were formed by sympodial growth from differentiated conidiophores on both media.
6) Repetitive or sympodial budding may be observed.
Most of the cerrado woody species presents a sympodial mode of growth with twisted and winding form of trunks and branches, as a consequence of fire impact on their growth form (Gottsberger and Silberbauer-Gottsberger, 2006).