Angiosperms: Dicotyledons

Lamiaceae
Mint Family

• Notes: Pycnanthemum tenuifolium is similar to P virginianum except the stem is smooth. The leaves are short and narrow (1” by 1/8” and smaller) and often with leafy shoots from the axils of the stem leaves. The inflorescence is similar, but the bracts below the flower heads are not hairy. The flowers and fruits are similar. Flowering is from mid- to late July, and fruiting begins in late July. P. tenuifolium is frequent on upland prairies and in open places.
• Bibliography from Biodiversity Heritage Library
• Vascular Plants of Iowa