Aquilegia micrantha Eastw.

Taxonomic Classification

Aquilegia micrantha Eastw. is a perennial herb that belongs to the columbine genus Aquilegia in the buttercup family Ranunculaceae. This species shows considerable natural variation.

Stem Morphology

Its stems reach 30 to 60 cm (12 to 24 inches) in height, and measure 1 to 3 mm (0.039 to 0.12 inches) in thickness.

Leaf Structure

Basal leaves growing from the base of the stem are bi- or triternately compound. Both stems and leaves may be lightly hairy.

General Aquilegia Flower Traits

All Aquilegia flowers have five sepals and five petals, and all Aquilegia flowers are bisexual.

Bloom Period

In wild populations, A. micrantha blooms from spring through summer, between April and September.

Flower Orientation and Sepal Color

Its flowers are either nodding or erect, and their sepals can be white, cream, blue, or pink. American botanist Philip A. Munz also recorded observations of reddish sepals in the species.

Sepal Dimensions

Sepals are 8 to 20 mm (0.31 to 0.79 inches) long.

Flower Blade Traits

The flower blades are white or cream, and 6 to 10 mm (0.24 to 0.39 inches) long.

Stamen Length

Stamens extend 3 to 5 mm (0.12 to 0.20 inches) beyond the blades.

Nectar Spur Traits

Nectar spurs are 15 to 30 mm (0.59 to 1.2 inches) long, straight, with inward-curving tips; spurs are either white or match the color of the sepals.

Spurless Variety

A spurless variety of this species, Aquilegia micrantha var. mancosana, has been documented.

Fruit Traits

Fruiting across the Aquilegia genus produces cylindrical follicles; on A. micrantha, these follicles measure 10 to 20 mm (0.39 to 0.79 inches) long.

Seed Size

The species produces seeds that are 1 mm (0.039 inches) long.

Geographical Distribution

Aquilegia micrantha is endemic to the Southwestern United States, where it occurs in southeastern Utah, southwestern Colorado, and extreme northern Arizona.

Habitat

It grows exclusively on hanging gardens in the canyons of the Colorado Plateau and Canyonlands, where alkaline water seeps from cliff bases.

Elevation Range

It grows most commonly at elevations between 1,000 m (3,300 ft) and 2,500 m (8,200 ft), which falls within the juniper belt ecological zone.

Hybridization

Because Aquilegia species have no genetic barriers to hybridization, they hybridize wherever overlapping ranges occur; A. micrantha hybridizes with A. elegantula at the eastern edge of its range.

Pollination Study Background

A 1983 study of pollination in A. micrantha in upper Crystal River Canyon, Colorado identified several species that act as pollinators.

Primary Pollinators

The most effective pollinators observed were bumblebee queens of Bombus appositus and Bombus flavifrons, which visited the plants to collect nectar.

Additional Pollinators

Hummingbirds and hawkmoths also visited A. micrantha, and hummingbirds are the most important pollinators of the species at other study sites.

Hybridization Reduction Mechanism

The study hypothesized that the low frequency of bumblebee visits to red-flowered Aquilegia elegantula acted as a mechanism to reduce hybridization between A. elegantula and A. micrantha.

Traditional Uses

Aquilegia micrantha has been used by the Navajo and Kayenta peoples to aid in childbirth.