Thlaspi arvense, known by the common name field pennycress,[1] is a flowering plant in the cabbage family Brassicaceae.

Thlaspi arvense is a foetid, hairless annual plant, growing up to 60 cm (24 in) tall,[2] with upright branches.

It blooms between May and July, with racemes or spikes of small white flowers that have 4 sepals and 4 longer petals.

[3] Later it has round, flat, winged pods with a deep apical notch,[2]: 141  measuring 1 cm (0.39 in) across.

[3] Other English common names are: stinkweed, bastard cress, fanweed, field pennycress, frenchweed and mithridate mustard.

Its seeds have a high oil content and the species has gained interest as a potential feedstock for biofuel production.

[8][9] Its area then extends through the Greater Caucasus, the Armenian Highlands, northwestern Iran, Kazakhstan, southern Siberia and up to the Pacific coast of Khabarovsk and Primorsky Krai, the Altai, Tian Shan and Pamir mountains, Korea and the Japanese Archipelago,[10] all but the southeasternmost provinces of China,[11] the mountains in the north of South Asia[10] (in parts of Nepal at 2000–4600 m,[12] in Indian Jammu and Kashmir and Ladakh, in Pakistan's Chitral, Hazara, Kurram Valley, and as far south as Rawalpindi District),[13] and Ethiopia.

This plant prefers disturbed areas, and its capacity to invade higher quality natural habitats is low.

[18] Fall establishment can provide early spring ground cover and suppress aggressive spring germinating weeds such as common lambsquarters (Chenopodium album), giant ragweed (Ambrosia trifida), and tall waterhemp (Amaranthus tuberculatus).

[18] Johnson et al. (2015) speculated that weed suppression may have been caused by allelopathic compounds rather than ground cover when pennycress seeding rates and companion crops were taken into account.

For good germination rates pennycress needs about 25-40mm of water and favours cold and wet conditions.

Generally cover crops like pennycress are used to take up the available nutrients to prevent them from leaching.

[4] In the Mid-western United States, its use as a rotation crop with soybean and maize maintains the pathogen Soybean Cyst Nematode (Heterodera glycines), though less effectively than other legumes[20] The first attempts to grow pennycress as an oil crop took place in 1994.

[4] Recently pennycress oil has attracted great interest as raw material for jet fuel and Biodiesel production.

Researchers have begun studying the genetics of pennycress in order to improve its potential use as a biofuel crop.