Clinopodium arkansanum (Low calamint)
Clinopodium arkansanum flower

Zone: 4 to 8

Soil: sand to loam

Light: Full sun to part sun

Bloom colour: Purple

Bloom period: Throughout the summer

Height: Less than 12 inches

Moisture: Usually dry to medium

Attracts: Small bees

Notes: This plant is also known as Calamintha arkansana. It is found all around the great lakes, the mid-atlantic and the midwest states. It is an excellent plant for attracting pollinators, but only if you plant it en masse. Due to its diminuitive size, it is a great plant for edging. Allow about 12 inches of space per plant. It spreads via stolons and within a few years, it will fill in the empty space.

The flowers have bilateral symmetry which is referred to as a zygomorphic shape. Since the flowers are not well clustered and are small, there is not much of a landing pad. Many pollinators are therefore excluded from taking advantage of these flowers. Small bees are the insects that can feed from Clinopodium and since most of the flowers are horizontal, the bees have to approach the flower from a specific direction. When they arrive at the flower, there is a relatively deep corolla so they either have to stick their head right in to reach the nectary or they need a long tongue. The short landing pad on the lower lip results in the bees not touching the protruding stamens on their way in. They touch the stigma inside the flower and deposit pollen from other flowers. There are stamens inside the flower, possibly guiding the bees to the nectary, but apparently, they are not functional. When the bee reverses out of the flower, they hit the protruding stamens and get a pollen load for the next flower.

It seems like a lot of work for a bee to visit these flowers, but in members of the mint family, nectar concentrations are high thus providing a decent reward. This relationship between the bee and the flower results in a highly efficient pollinator partnership. The plant is long blooming so it is an excellent nectar plant for the garden,

This plant grows best in a well-drained calcareous soil. It can survive with little watering, but it will look its best if given supplemental watering in the garden. Due to its diminuitive size, it should be planted at the front of the border. It is also an excellent spill plant in containers and it will continue to grow in length well into fall.

Clinopodium arkansanum - Low calamint
Inside the flower of Clinopodium arkansanum
The stamens of Clinopodium are didynamous. They consist of 2 pairs of stamens with one pair protruding from the flower. Usually, the protruding pair of stamens is the most important for pollen presentation.
Clinopodium arkansanum
The flowers are in very loose clusters.
Clinopodium arkansanum in containers
Clnopodium arkansanum being used as a spill plant. Reference: Willmer, P. 2011. Pollination and floral ecology. Princeton University Press.
Full shot of Clinopodium arkansanum
Clinopodium arkansanum