Biomorph Limosella aquatica L. and its contribution in stolon-rosette water grasses formation

Abstract

The paper presents comparative-morphological analysis of biomorphs Limosella aquatica L., stolon-rosette perennial mesophyte grasses (Viola odorata L.), and yearling vegetative hydrophytes (Stratiotes aloides L. and Hydrocharis morsus-ranae L.). It is shown that L. aquatica is a monopodial growing monocarpic with side stolon-rosette shoots and their systems with up to four branching orders. The primary shoot, as well as rosette parts of stolon-rosette shoots, is made of metamers with foliage leafs, axil complexes with differently sets of constituents: two collateral buds and/or their derivatives: flower buds/flowers/fruit, side stolon-rosette shoots or their systems. At the initial stage the shoot-forming mode of L. aquatica is similar to that of V. odorata: a monopodial rosette one with green assimilating leaves, flowers, and stolon-rosette shoots. But iterative branching of stolon-rosette shoots changes the shoot-forming mode of L. aquatica to a sympodial semirosette as in S. aloides, and especially in H. morsus-ranae. Biomorph L. aquatica combines the features of stolon-rosette perennial mesophyte grasses and stolon-rosette yearling vegetative hydrophytes: stolon-rosette shoot formation from axil buds, iterative branching, collateral buds, reduction inflorescence to one flower (S. aloides). Thus of habit L. aquatica can be viewed as a stage of perennial flower mesophyte plants’ shifting to life in water.

A monopodial rosette model of shoot formation as a program of secondary-aquatic grasses appearing

“…During a vegetation period each metamer of the original specimen develops axillary complexes from the dormant main and successive buds with many fruit. Along the axis of the shoot these complexes change in the following succession: a fruit, a stolon-rosette shoot or a system of them; a flower and a bud; a flower bud and a bud [16]. The mentioned structures, homologues as for their place on the axis, demonstrate a possible transformation of lateral specialized shoots into one flower.…”

Life strategies of plants of meander bars

“…It mostly grows on limous and sandy shores, shoal heads, in drying bottoms of water bodies, ditches, pools, on flood plains and soddy meadows [13]. It is a monopodially growing rosette polycentric monocarpic with a monopodial rosette model of shoot formation, lateral stolon-upper-rosette shoots, and their systems up to four branching orders [14]. During a vegetation season lateral shoot systems are formed continuously from the buds of the leading and lateral shoots.…”

“…Such a kind of shoot formation is analogous to iterate branching (continuous formation of several successive replacement shoots forming the axis of the plant during a vegetation period) typical to grass hygrophytes and hydrophytes. Formation of axillary complexes leads to increasing the assimilating surface, as well as of the energy of seed reproduction of specimens, it contributes to their prolonged in time fruiting and active dispersion [14]. Seed production can reach 1500 seeds per one plant.…”