Floral organogenesis of Potamogeton distinctus A. Benn. (Potamogetonaceae)

›› 2000, Vol. 38 ›› Issue (6): 528-531.

SUN Kun, ZHANG Zhi-Yun, CHEN Jia-Kuan

Abstract:

The floral organogenesis of Potamogeton distinctus A. Benn. was observed under the

scanning electron microscope (SEM). The floral buds are first initiated on the lower portion of inflo-

rescence in alternating whorls of three. Each of the floral buds is subtended by a bract primordium

during the early stages. The primordia of the floral appendages arise on the floral bud acropetally.

Two lateral tepals are first initiated and then two median ones soon after. Stamens are normally initi-

ated as elongate primordia opposite the tepals, with the two lateral stamens preceding the median

ones. The two carpel primordia arise alternating with the stamens. In some flowers, one of the two

gynoecial primordia becomes inactive soon after they are initiated, or only one carpel primordium is

initiated. The present observation of the gynoecial development supports the viewpoint that the evo-

lution of flower in Potamogeton involves a reduction in number of parts. The existence of bract pri-

mordium during the early stages in many species of Potamogeton indicates that the absence of bract

in mature flowers should be the result of reduction.

Key words: Potamogeton distinctus, Floral organogenesis

SUN Kun, ZHANG Zhi-Yun, CHEN Jia-Kuan. Floral organogenesis of Potamogeton distinctus A. Benn. (Potamogetonaceae)[J]. , 2000, 38(6): 528-531.

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