Juha Suominen & Leena Hämet-Ahti 1993: Kasvistomme muinaistulokkaat: tulkintaa ja perusteluja. (Archaeophytes in the flora of Finland.) Norrlinia 4: 1–90. ISSN 0780-3214. ISBN 951-45-6373-5

Retkeilykasvio, the Field Flora of Finland contains a map for each species and for many lower taxa to show the plant’s status within the biogeographical provinces in the following classes: native (present of extinct) – established alien – casual alien. In the third edition (Hämet-Ahti et al. 1986; summary on page 598) an attempt is made to distinguish the truly native (indigenous) plants and the archaeophytes which invaded Finland or its given provinces long ago with the aid of man. The chronological limit between the archaeophytes and the later immigrants (neophytes) is placed in the early 17th century. The arguments for the national or regional archaeophytic status have never been published in detail for the whole Finnish flora and for the whole of the country. In this paper a lot of these arguments are presented in Finnish because a) numerous highly local matters and details are discussed and b) our purpose is just to promote the study in this field of Finnish botany to show what is known and what is not known and what perhaps will remain a riddle forever. As said above the concise results of this paper have been published in advance on the maps of Retkeilykasvio (Hämet-Ahti et al. 1986). However, now a number of its maps are shown or suspected to be erroneous in some details or even entirely.