Arabidopsis thaliana

Arabidopsis thaliana, thale cress or mouse-ear cress, is small herbaceous annual flowering plants in the Brassicaceae (mustard family, which also includes cabbage and broccoli). As noted in the Flora of North America (2012) “Arabidopsis thaliana is the most widely used model organism in plant biology. Its small genome size, fully sequenced in the year 2000, chromosome number, fast growth cycle (from seed germination to set in four to six weeks), small size (hundreds can be grown in a pot and thousands in a growth chamber), autogamous breeding system (induced mutations are expressed in two generations), and ability to grow on various synthetic media, all make the species an ideal system in experimental biology.”

A. thaliana is a small plant, 2 to 25 cm (1 to 9.5 in) in height, with a basal rosette of leaves that are 0.8 to 3.5 cm (0.3 to 1.3 in) long and up to 1 cm (0.4 in) wide; cauline leaves (on the flowering stem) are smaller. The small white flowers, which are less than 0.5 cm in diameter, have 4 petals and develops into a siliqua (a seed capsule or pod) that contains 20-30 small plump tan brown seeds, each 0.5 mm or less in diameter.

A. thaliana originated in Europe and central, southwest Asia, and northern Africa, but has been introduced and naturalized throughout the U.S. and Canada, and has been introduced in nearly worldwide. Like many species in the Brassicaceae, A. thaliana are edible by humans, and can be used similarly to other mustard greens, in salads or sautéed, but its use as an edible spring green is not widely noted. It is generally considered a weed, due to its widespread distribution in agricultural fields, roadside, and disturbed lands.

The large amount of research and genome information on A. thaliana is compiled in online sources including The Arabidopsis Information Resource (TAIR) (http://www.arabidopsis.org/), Arabidopsis Biological Resource Center, (ABRC) based at Ohio State University (http://abrc.osu.edu/), and Nottingham [European] Arabidopsis Stock Centre (http://arabidopsis.info/)).

(FNA 2012, NSF 2012, Wikipedia 2012.)

This is one of many weedy annuals in the Mustard family that is native to Eurasia. Mouse-Eared Cress resembles a cross between a Draba sp. (Whitlow Grass) and an Arabis sp. (Rock Cress). It is the only member of its genus in Illinois. Species of Whitlow Grass have seedpods that are more short and fat than those of Mouse-Eared Cress, while species of Rock Cress are usually larger in size. A possible exception is Arabis lyrata (Sand Cress), which has larger flowers (about ¼" across) and basal leaves that are slightly pinnatifid, rather than entire. Although larger in size, Arabis hirsuta (Hairy Rock Cress) is somewhat similar in appearance to Mouse-Eared Cress. However, Hairy Rock Cress has lower cauline leaves that clasp the stem and its seedpods are flattened, rather than terete.

This accidentally introduced plant is a winter annual, consisting of a small rosette of low basal leaves and an erect flowering stalk about 3–12" tall. The basal leaves are ½–2" long and ¼–½" across; they are dull green to red, lanceolate-oblong to oblanceolate-oblong, hairy on both their lower and upper sides, and smooth to slightly toothed along their margins. The central stem is unbranched or sparingly branched in the upper half. It is terete, light green to reddish brown, and hairy toward the base, becoming glabrous toward the apex. The erect to ascending cauline leaves develop alternately along each stem and they are few in number (typically 1-5 per plant). Cauline leaves are ½–1" long and 1/8–1/4" across; they are dull green to reddish brown, narrowly elliptic-oblong, smooth along their margins, hairy, and sessile.  The central stem (and upper side stems, if present) terminates in an elongated raceme. The flowers and buds are crowded together near the apex of the raceme, while developing seedpods are located below. Each tiny flower is about 1/8" across, consisting of 4 white petals (not cleft at their tips), 4 light green sepals, a pistil with a single style, and several stamens. The sepals are erect and lanceolate; the petals are a little longer than the sepals. The blooming period occurs during the spring and lasts about 1½ months. Each flower is replaced by a hairless silique (narrow cylindrical seedpod) about ½" long. The ascending siliques are straight or curved slightly upward; they have short petioles up to ¼" long. Inside each silique, there are several tiny seeds that are arranged in a single row. The root system consists of a shallow branching taproot with fine secondary roots. This plant reproduces by reseeding itself.

Mouse-Eared Cress is occasional in the southern half of Illinois, but rare or absent in the upper half of the state (see Distribution Map). It may be spreading northward, however. Habitats include fields, pastures, roadsides, areas along railroads, gravelly or sandy paths, and barren waste areas. Disturbed habitats are preferred. Mouse-Eared Cress is native to Europe and northern Asia.

Arabidopsis thaliana (L.) Heynh.:
Canada (North America)
India (Asia)
Japan (Asia)
Kazakhstan (Asia)
Mongolia (Asia)
Russian Federation (Asia)
South Korea (Asia)
Tajikistan (Asia)
United States (North America)
South Africa (Africa & Madagascar)
China (Asia)
Uzbekistan (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Anhui, Gansu, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan, Xinjiang, Xizang, Yunnan, Zhejiang [India, Japan, Kazakhstan, Korea, Mongolia, Russia, Tajikistan, Uzbekistan; Africa, SW Asia, Europe, North America].

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Distribution: Mediterranean region, Europe and Temp. Asia.; introduced else-where.

Temperate Eurasia, Africa.

Annual, 5-20 (-45) cm tall, erect, simple or branched, usually from the base, often hairy below and suhglabrous above with short, branched or simple hairs. Basal leaves rosulate, obovate-oblong, 15-50 mm long, 5-10 mm broad, subsessile, slightly to distinctly toothed or entire; upper leaves, short, distant, oblong or linear, cuneate below. sessile. entire or obscurely toothed. Racemes (8-) 15-30 (-40)-flowered, up to 20 cm long in fruit. Flowers 2-3 mm across, white or pale pinkish; pedicels (5-) 8-15 mm long in fruit, filiform, subspreading or ascending. Sepals 1.5-2 mm long. Petals 3-4 mm long, 1 mm broad. Stamens 6 or 4, c. 1.5: 2.5 mm long (outer 2 sometimes suppressed) ; anthers c. 0.5 mm long. Siliquae (10-) 12-18 mm long, 1 mm broad, linear, subcylindrical, often somewhat upcurved, glabrous; valves 1-veined; stigma short, depressed, sub-sessile or on c. 0.5 mm long style; septum not veined; seeds usually 20-30 in each locule, c. 0.5 mm long.

Herbs annual, (2-)5-30(-50) cm tall. Stems erect, 1 or few from base, simple or branched above, basally with predominantly simple trichomes, apically glabrous. Basal leaves shortly petiolate; leaf blade obovate, spatulate, ovate, or elliptic, 0.8-3.5(-4.5) cm × (1-)2-10(-15) mm, adaxially with predominantly simple and stalked 1-forked trichomes, margin entire, repand, or dentate, apex obtuse. Cauline leaves subsessile, usually few; blade lanceolate, linear, oblong, or elliptic, (0.4-)0.6-1.8(-2.5) cm × 1-6(-10) mm, entire or rarely few toothed. Fruiting pedicels slender, divaricate, straight, 3-10(-15) mm. Sepals 1-2(-2.5) mm, glabrous or distally sparsely pubescent with simple trichomes, lateral pair not saccate. Petals white, spatulate, 2-3.5 × 0.5-1.5 mm, base attenuate to a short claw. Filaments white, 1.5-2 mm. Ovules 40-70 per ovary. Siliques linear, terete, smooth, (0.8-)1-1.5(-1.8) cm × 0.5-0.8 mm; valves with a distinct midvein; style to 0.5 mm. Seeds ellipsoid, plump, light brown, 0.3-0.5 mm; cotyledons incumbent. Fl. and fr. Jan-Jun(-Oct). 2n = 10*.

2300 m

Arabis thaliana Linnaeus, Sp. Pl. 2: 665. 1753; Sisymbrium thalianum (Linnaeus) J. Gay & Monnard; Stenophragma thalianum (Linnaeus) Celakovsky.

Mouse-Eared Cress is occasional in the southern half of Illinois, but rare or absent in the upper half of the state (see Distribution Map). It may be spreading northward, however. Habitats include fields, pastures, roadsides, areas along railroads, gravelly or sandy paths, and barren waste areas. Disturbed habitats are preferred. Mouse-Eared Cress is native to Europe and northern Asia.

Plains, mountain slopes, river banks, roadsides; near sea level to 2000 m.

Little information is available about floral-faunal relationships for this species. The tiny flowers are probably cross-pollinated by small bees and flower flies (Syrphidae). In the absence of such visitors, the flowers are undoubtedly self-fertile.

Foodplant / feeds on
larva of Ceutorhynchus atomus feeds on Arabidopsis thaliana

In Great Britain and/or Ireland:
Foodplant / parasite
colony of sporangium of Peronospora parasitica parasitises live Arabidopsis thaliana
Remarks: season: 1-4

Fl. Per.: April-June.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 32
Specimens with Barcodes: 39
Species With Barcodes: 1

Rounded Global Status Rank: GNR - Not Yet Ranked

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Typical growing conditions include full sun, a mesic to dry location, and barren soil that is sandy or gravelly. This little plant develops quickly during the cool weather of spring and withers away no later than early summer.