Palaeofloristics

Abstract

As a simplification, it may be said that floristics treats of the geographical distribution of taxa, the plotting of the plant system against the geographical background. In palaeofloristics we are concerned with both the spatial distribution and the chronological ranges of the taxa. Palaeofloristics may be defined as the study of the distribution of the taxa — in time and space. By plotting the taxa areas on maps we observe the concentration of the boundaries in certain areas of the Earth. This implies that the taxa form natural associations, each of which is confined to a definite territory. It can also be seen that the associations are inlain one in another, forming a system of subordination. Each association corresponds to a territorial floristic unit — the phytochorion. Phytochoria may be of different ranks. In descending order they are as follows: kingdom, area, province, district, region. Each is denoted by a specific geographical name. The taxa list of a phytochorion or its part is termed flora.