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There are four taxa in this species group in Alberta, consisting of the Anise Swallowtail (P. zelicaon) and three subspecies of the Old World Swallowtail (P. machaon). The Anise Swallowtail occurs together with P. machaon throughout most of Alberta, and the following characters will distinguish these two species in most cases: the black pupil of the hindwing eyespot is connected to the wing margin or positioned below the red scales in P. machaon, compared to a centered, unconnected pupil in zelicaon. Occasionally, hybrid individuals displaying characters intermediate between P. m. dodi and P. zelicaon are found, while hybrids between other machaon subspecies and zelicaon can be quite common in some areas (Sperling 1987, 1990). Subspecies of P. machaon are best distinguished by location and habitat. P. m. pikei occurs in habitat similar to that of P. m. dodi, but is restricted to the Peace River grasslands. The Hudsonian Old World Swallowtail (P. m. hudsonianus) is a boreal forest species generally associated with sparsely wooded bogs. To add to the challenge in identifying members of this group, a black color form occurs rarely in populations of P. m. dodi (but not pikei or hudsonianus), in which adults have most of the yellow colouration replaced by black (Sperling 1987). This form more commonly occurs in the Anise Swallowtail (P. zelicaon) and hybrids between P. machaon and P. zelicaon. Differences in mitchondrial DNA also distinguish P. machaon from P. zelicaon (Sperling & Harrison 1994).

Eggs are yellow and spherical. First to third instar larvae are black with a white 'saddle', and resemble bird droppings. Mature larvae of P. m. dodi are bright green to blue-green with black bands and orange (very rarely yellow) segmental spots (Sperling 1987). Pupae are variegated brown or green and may overwinter more than once, possibly to avoid drought conditions in poor years (Bird et al. 1995). Adult males seek out hill tops or prominent ridge tops along river valleys to await females.

The only larval foodplant is Tarragon (=Dragonwort) (Artemisia dracunculus) (Sperling 1987). Adults take nectar at groundsel (Senecio spp.), hedysarum (Hedysarum spp.) and alfalfa (Medicago sativa) (Bird et al. 1995).

Dod's Old World Swallowtail occurs from the southern Kootenay River valley of southeastern BC and the Battle River valley of Alberta east to southeastern Saskatchewan, south into the adjacent U.S. (Sperling 1987, Guppy & Shepard 2001, Schmidt unpubl. data). The type specimens were collected near Dorothy, Alberta (Kondla 1981) by one of Alberta's foremost pioneer lepidopterists, F.H. Wolley Dod.