Nota preliminar sôbre a variação em orquídeas brasileiras

Brieger, F. G.

doi:10.1590/S0071-12761951000100032

Resumo

Preliminary studies on brazilian orchid species show that the existing material offers the possibility for studying the following general questions: a) In spite of the rule about the relative proportion between numbers of individuals per species and number of species per unit area in tropical and in temperate zones, the orchid genera seem to follow more closely the rule of temperate zone species, and this in spite of the fact that the family is undoubtedly of tropical origin. b) The large amont of paralell variation existing between different genera recquires a detailed explanation, and extensive introgressive hybridization is mentioned as one possibility. c) The existence of natural sympatric hybrids, both inter-generic and interspecific, and the simultaneous existence of the species in the pure form, show that mechanismes of reproductive isolation must exist, though of an incomplete nature.

Secção de Genética Escola S. A. "Luiz de Queiroz" Piracicaba

SUMMARY

Preliminary studies on brazilian orchid species show that the existing material offers the possibility for studying the following general questions:

a) In spite of the rule about the relative proportion between numbers of individuals per species and number of species per unit area in tropical and in temperate zones, the orchid genera seem to follow more closely the rule of temperate zone species, and this in spite of the fact that the family is undoubtedly of tropical origin.

b) The large amont of paralell variation existing between different genera recquires a detailed explanation, and extensive introgressive hybridization is mentioned as one possibility.

c) The existence of natural sympatric hybrids, both inter-generic and interspecific, and the simultaneous existence of the species in the pure form, show that mechanismes of reproductive isolation must exist, though of an incomplete nature.

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BIBLIOGRAFIA

Entregue para a publicação em 31-10-1951

COGNIAUX, A., 1902 - Orchidaceae. Laeliinae Martius, Flora Brasiliensis Vol. III, 5.
PFITZER, E., 1889 - Orchidaceae Engler-Prantl, Die natuerlichen Pflanzen-familien, II, 6.
SCHLECHTER, R. 1917 - Die Einteilung der Gattung Laelia und die geographische Verbreitung ihrer Gruppen. Orchis 9: 87-96.
SCHLECHTER, R., 1927 - Die Orchideen. Berlin, Parey.