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 ?
The PC-I showed maximum variation (26.15%) which was mainly due to the sympodial branches, monopodial branches, bolls per plant and seed cotton yield per plant.
In parental lines, CRIS-134 formed 1st sympodial node at the lowest node of 7.50 being earlier while FH-113 formed 1st sympodia at the highestnode of 10.15, thus it was considered as a late maturing parent.
Plant height, number of bolls per plant, number of sympodial and monopodial branches markedly influenced by interactive effect of sowing dates (SD) and genotypes (G).
Maximum SCA was observed in the trait sympodial branches per plant, with the hybrid CIM-497 x NIAB-999 (1.87) and the least SCA values were observed in cross BH-160 x RH-510 (SCA = -1.01).
Leaf blade oblong-elliptic to elliptic-ovate, 13-45 cm long; base asymmetrical in sympodial leaves, cordate to deeply auriculate, the biggest lobe half or completely overlapping the petiole; pinnately veined with 8-16 secondary veins; ciliate and minutely pubescent on both surfaces.
microphylla is a sympodial bamboo with pachymorph rhizomes [26], which are extremely hardy and grow 20 cm deep into the soil [27].
Chamaesyce is characterized by many unusual synapomorphies: apical abortion of the main shoot and subsequent sympodial growth; interpetiolar stipules; opposite and frequently asymmetrical leaves; and [C.SUB.4] photosynthesis (KOUTNIK, 1984, 1987).
Mucor fragilis sympodial branching pattern; taken with Q Imaging digital microscopy and recorded through Image Pro Express.