Within this pattern, the Cypereae spikelets show variations in (Tables 1 and 2): (A) number and phyllotaxis
of the glumes; (B) presence of empty glumes (lack of development of flowers in lower or upper glumes); (C) glume morphology; (D) rachilla internode length; (E) prophyll development; (F) flower structure; (G) structure of the dispersal unit.
The descriptors were: (i) leafblade division;(ii) leaf composition; (iii) petiole length in relation to leaf blade; (iv) phyllotaxis
, (v) leaf position in relation to the branch insertion; (vi) leaf shape; (vii) leaf apex and base angles; (viii) leaf margin category; (ix) venation; (x) leaf length and thickness; (xi) leaf length/thickness ratio; (xii) leaf texture; (xiii) leaf fragrance; (xix) leaf color.
However, the opposite phyllotaxis
and the small leaves of G.
The opposite phyllotaxis
for the eophylls of the seedlings of Serjania communis may be considered as exceptional in the Macaranga type, since the first few leaves of the Macaranga are, in most cases, all spirally arranged.
In nature, alternate phyllotaxis
is more common, as is shown in Fig.
Observations on phyllotaxis
, stelar morphology and gemmae of Lycopodium lucidulum (Lycopodiaceae).
also shows that not only do leaves grow around a stem using this angle, and not only do the florets on the head of a sunflower grow accordingly, but they also grow in interleaving logarithmic spirals which number according to Fibonacci pairs.
Biologists now understand the basic biochemistry that drives patterns of plant growth, called phyllotaxis
, and that knowledge has fed into mathematical and computer-based models of the process.
Concepts based on a symmetrical structure were abandoned for a pattern of spirals, based on the Fibonacci series and phyllotaxis
(the mathematical basis for most plant growth), which will re-appear-in the sculpture that will sit almost hidden in the core of the Core.
Pistia plants produce a rosette of leaves in a alternate spiral phyllotaxis
To highlight the mathematical underpinnings of phyllotaxis
, which refers to the arrangement of leaves or other botanical elements around a stem, Gole and Pau Atela, associate professor of mathematics, teamed up with Michael Marcotrigiano and Madelaine Zadik of the Smith College Botanic Garden to produce an exhibition, "Plant Spirals: Beauty You Can Count On" (www.
Contains reviews on organization and function of meristems, meristem formation in embryogenesis, genetic control of reproductive meristems, axillary meristem development, phyllotaxis
, axial patterning, regulation of cell division, and the root meristem.