Veronica arvensis (common names: wall speedwell,:592 corn speedwell, common speedwell, rock speedwell,), field speedwell is an annual flowering plant in the plantain family Plantaginaceae. The species is a native European plant and a common weed in gardens, pastures, waste places and cultivated land.
It is a hairy, erect to almost recumbent, annual herb, 9 to 40 centimetres (3.5 to 15.7 in) high from a taproot. The leaves are oppositely arranged in pairs about the stem. The lower leaves have short petioles; the upper are sessile. Each leaf, 1.5 to 2.5 centimetres (0.59 to 0.98 in) in length, is ovate, or triangular with a truncated or slightly cordate base, with coarse teeth. Borne in a raceme, initially compact but elongating with age, the flowers are pale blue to blue-violet, 2 to 3 mm in diameter, four-lobed with a narrow lowest lobe. Flower stalks are 0.5 to 2 millimetres (0.020 to 0.079 in) and shorter than the bracts. The fruit capsules are heart-shaped and shorter than the sepal-teeth. It flowers from April to October.
V. arvensis plants go through changes in their germination due to temperature and light, furthermore explaining what controls the timing of growth in buried seed reserves. These weeds tend to germinate in consistent temperature ranges of 10 degrees Celsius to 15 degrees Celsius. If they do not make the first autumn cycle of growth, they can grow in the following spring. Overall, light is a major source to their survival and growth. In other words, they can grow in darkness, however they will remain dormant unless they get light.
- Stace, Clive (April 2010). New Flora of the British Isles. ISBN 9780521707725.
- Veronica arvensis at USDA PLANTS Database
- Popay I., Champion P. & James T. (2010). An Illustrated Guide to Common Weeds of New Zealand, Third edition. p. 286. New Zealand Plant Protection Society (Inc.), Christchurch, New Zealand. ISBN 978-0-473-16285-6.
- Veronica arvensis Archived 2015-09-24 at the Wayback Machine. at Germplasm Resources Information Network - (GRIN)
- Baskin, Jerry; Baskin, Carol (March 1983). "Germination Ecology of Veronica arvensis". Journal of Ecology. 71 (1): 57–68. doi:10.2307/2259963.
- Veronica arvensis at Plants For A Future
King, T.J (July 1975). "Inhibition of Seed Germination Under Leaf Canopies in Arenaria serpyllifolia, Veronica arvensis and Cerastum holosteoides". New Phytologist. 75 (1): 87–90. doi:10.1111/j.1469-8137.1975.tb01374.x.
|Wikimedia Commons has media related to Veronica arvensis.|