منابع مشابه
Vascular phyllotaxis transition and an evolutionary mechanism of phyllotaxis
Leaves of vascular plants are arranged regularly around stems, a phenomenon known as phyllotaxis. A constant angle between two successive leaves is called divergence angle. On the one side, the divergence angle α0 of an initial pattern of leaf primordia at a shoot apex is most commonly an irrational number of about 137.5 degrees, called limit divergence. On the other side, the divergence α of a...
متن کاملRegulation of phyllotaxis.
Plant architecture is characterized by a high degree of regularity. Leaves, flowers and floral organs are arranged in regular patterns, a phenomenon referred to as phyllotaxis. Regular phyllotaxis is found in virtually all higher plants, from mosses, over ferns, to gymnosperms and angiosperms. Due to its remarkable precision, its beauty and its accessibility, phyllotaxis has for centuries been ...
متن کاملOn geodesics of phyllotaxis
1: Seeds of sunflowers are often modelled by the map n 7−→ φθ(n) = √ ne2iπnθ leading to a roughly uniform repartition with two consecutive seeds separated by the divergence angle 2πθ for θ the golden ratio. We associate to an arbitrary real divergence angle 2πθ a geodesic path γθ : R>0 −→ PSL2(Z)\H of the modular curve and use it for local descriptions of the image φθ(N) of the phyllotactic map...
متن کاملPhysical phenomenology of phyllotaxis.
We propose an evolutionary mechanism of phyllotaxis, regular arrangement of leaves on a plant stem. It is shown that the phyllotactic pattern with the Fibonacci sequence has a selective advantage, for it involves the least number of phyllotactic transitions during plant growth.
متن کاملGeometric interpretation of phyllotaxis transition
The original problem of phyllotaxis was focused on the regular arrangements of leaves on mature stems represented by common fractions such as 1/2, 1/3, 2/5, 3/8, 5/13, etc. The phyllotaxis fraction is not fixed for each plant but it may undergo stepwise transitions during ontogeny, despite contrasting observation that the arrangement of leaf primordia at shoot apical meristems changes continuou...
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ژورنال
عنوان ژورنال: The American Naturalist
سال: 1873
ISSN: 0003-0147,1537-5323
DOI: 10.1086/271177