Arabidopsis lyrata (L.) O'Kane & Al-Shehbaz

Species Identity and Growth Form

Arabidopsis lyrata (L.) O'Kane & Al-Shehbaz is a diploid perennial plant, reaching 10–40 centimetres (4–16 in) in height.

Basal Leaves and Flower General Appearance

It has highly distinct basal leaves, and small pure white flowers.

Stem Leaf Morphology

Stem leaves are arranged alternately, with linear, slightly curved smooth margins and tapered bases.

Leaf Defense Mechanisms

The species’ leaves produce glucosinolates and have trichomes, which act as defense mechanisms against insect herbivores and other potential threats such as fires and human activity.

Individual Flower Size

Individual flowers are very small, measuring 3–8 mm across.

Flower Structure and Pedicel Characteristics

They have four lobes, and grow on widely ascending pedicels that are 7 to 12 mm long.

Pollination and Reproductive Timing

This species is insect pollinated, and blooms from May through June, with fruits developing in early August.

Fruit Morphology

Fruits are elongated, papery, and 2–4.5 millimetres (0.08–0.18 in) long.

Seed Characteristics

Seeds are 1 mm (0.04 in) long and arranged in a single row.

General Habitat Range

Arabidopsis lyrata occurs mostly in subarctic or subalpine areas with thin soils, including rock faces, eskers, talus slopes, and exposed coastal zones.

Growth Form and Asexual Reproduction

Individual plants can grow as solitary rosettes, and reproduce asexually through clonal patches.

Competitive Habitat Requirements

This species cannot survive in agro-ecosystems with abundant weeds, and grows best under low competition.

Life Cycle Light Requirements

Its life cycle relies on completing germination, growth, and seed set in a very short window before other plant species block access to light.

Global Distribution

It has a circumpolar distribution, found across northern and central Europe, Asia, and North America.

Virginia Habitat Specifics

In the U.S. state of Virginia, it grows in rocky woodlands, barrens, and crevices or thin-soiled ledges on outcrops of limestone, dolomite, siltstone, metasiltstone, amphibolite, metabasalt, diabase, and other mafic and felsic igneous and metamorphic rocks.

Eastern U.S. Habitat

It also occurs in eastern United States, where it is usually restricted to sand bars.

European Distribution

In Europe, it is found in southern Germany and restricted areas of Sweden.

Mating System Variation

For North American populations of Arabidopsis lyrata ssp. lyrata, outcrossing is typical in the center of the species’ range, while populations at range margins shift toward selfing.