In botany tentative attempts have been made to classify species, based
not on the plant as a whole, but on a particular character, for examp
le pollen characteristics. Pollen, which is involved in the transmissi
on of male genetic information during sexual reproduction, is of parti
cular interest in distinguishing plants and their relationships. These
characters, observed in photon- and scanning electron- microscopy are
symmetry, form, number and position of germinating areas. Being genet
ically stable for a given species, they identify a plant. Recently, a
novel character has been added: the concentration of elements in the e
xine, determined by electron probe micro-X-ray analysis. It is interes
ting to follow relationship of plant species, based on the mineral com
position of their pollen as a whole, taking into account both plastic
and oligoelements, obtained via an inductive coupled plasma spectromet
er. Samples of pollen from different plant species, at distinct taxono
mic levels, were analyzed; the results were submitted to a normalisati
on procedure and the standard patterns obtained were investigated by m
eans of a number of numerical techniques (clustering and factor analys
is). The aim was to establish if elements could be considered as chemi
cal markers in plant cladistics. The mineral composition in a given sp
ecies appeared quite stable and this furnished a convenient identifica
tion-critorion. This approach further allows a chemo-taxonomy of speci
es, in as much as organization of families, and perhaps orders, would
conform to the phylogenetic proximity-criterion. Hence, we found clust
ers including pollen of Gramineae, Coniferae, Betulaceae.... This meth
odology, that should be completed and corroborated on a wider range of
samples would provide an original responsee to the problems of identi
fication and classification encountered in a pollen bank. It follows t
hat: the pattern of pollen composition of oligo-elements, calcium and
magnesium is a marker in plant cladistics. Since a typology depending
on proximity is found between plant species, families and orders. an u
nknown pollen sample may be located, tentatively, on the base of a des
cribed model of pollen relation (shortest connexion network - Prim alg
orithm - and pollen of Bactris-oil palm and Phoenix dactylifera). Henc
e, the working hypothesis that the chemical markers and, in particular
, oligo-elements, complete pollen typologies based on morphological an
d structural characters, appears quite reasonable. In conclusion, this
paper brings a complement to the mineral composition of the exine.