The Lamiaceae are anything but lame. Most of its members are herbaceous plants with SIMPLE, OPPOSITE leaves and SQUARE STEMS.
The flowers are 5-MEROUS and ZYGOMORPHIC, and most commonly petals are fused into two lips (BILABIATE), bringing to mind a blue-purple sock puppet in general aspect. As seen in the photo above, the upper lip is often much REDUCED and the broad lower lip may have coloration patterns that act as NECTAR GUIDES. The CALYX can vary from two-lipped to regular and is often a more reliable character for keying purposes because the petals fall off quickly as the fruit develops (Michigan Flora). The flowers have 2 or 4 EPIPETALOUS STAMENS. The ovary is DEEPLY LOBED and looks like a 4-pack of hot cross buns when views from above. The ovary lobes develop into 4 NUTLETS.
The inflorescence is either a terminal spike, as in bugle weed (Ajuga reptans), or a +/- tight axillary or terminal cluster of flowers, as in wild basil (Clinopodium vulgare), bee balms/ bergamots (e.g. Monarda fistulosa), and mint (Mentha arvensis). Mint flowers are most often purple or white, or some combination of the two.
One of the easiest ways to tell a member of the mint family is to crush a leaf and take a whiff. The stems and flower parts of many species are dotted with resin glands that seep aromatic oils, making them pleasant additions to your garden, your tea cup, or your kitty’s diet (catnip, Nepeta spp). Some specialist bees visit mints to harvest oils, as well as nectar and pollen.
Many mints appear as cultivars in flower gardens, including Salvia’s, bee balms, spearmint, and lemon balm.
WEEDY OHIO MINTSThis is arguably the most abundant mint in Ohio, Glechoma hederacea (gill-over-the-ground or ground ivy). It is a weedy, aromatic, creeping plant with tiny purple flowers. **Know this one for the quiz in class.
Monarda fistulosa, wild bergamot, produces a terminal cluster of lilac-colored flowers in early summer. It is a hardy plant and is often planted in gardens and prairie restoration projects because of its attractiveness to pollinators.
Pycnanthemum virginianum (Virginia mountainmint) is a another plant that is highly attractive to pollinators, though rarely found growing wild in Ohio. Pycnanthemum muticum is more commonly found here along edges of woods in early summer. In the photo above, a honey bee is approaching a flower. Pycnathemum spp. produce copious amounts of nectar that attract many guilds of pollinators, which results in large amounts of tiny fruits (mouse over image).
Teucrium canadense, Canada germander or wood sage, is a robust plant with pale purple-pink flowers in late summer. May be weedy in some places in the U.S., but plays nicely with others in Ohio. Seen growing in large patches along roadside ditches in late summer.
MINTS OF MOIST HABITATS
Lycopus americanus (water horehound) is a common, at times weedy, mint of wet places like the edges of marshes or woodland pools. Note the axillary clusters of small white flowers and coarsely blunt-toothed leaves.
Scutellaria incana, hoary skull cap. Scutellaria spp. is genus of woodland herbs that are usually found on floodplains and the edges of wetlands that are not saturated year round. They are not rare, but not abundant either. The most common species is mad dog skullcap (Scutellaria lateriflora).