Arvensis:  Answers to key questions in Budd's Flora leading to this species.   flowers in axillary clusters, not terminal spikes

 

Mentha: Answers to key questions from Budd's Flora and Flora of Alberta leading to this genus. leaves crenate to serrate, NOT palmately lobed inflorescences axillary flowers in axillary clusters; NOT solitary, NOT in axillary racemes flowers pedicellate flowers blue or lavender calyx indistinctly 2-lipped or regular calyx WITHOUT projection on upper side calyx WITHOUT hooks at tips of lobes corolla nearly regular (FOA), 4- or 5- lobed; hardly, if at all, 2-lipped 4 anther-bearing stamens stamens equal in length

Labiatae: Answers to key questions from Budd's Flora leading to this family. herbs plants green or with some chlorophyll plants NOT aquatic stems square leaves NOT bearing bladders leaves opposite flowers NOT in heads or spikes flowers with two floral rings, but with the petals wholly or partly united forming a tube or bell corolla irregular ovary superior fruit with 4 nutlets