Planodes virginicum
| Planodes virginicum | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Planodes virginicum | ||||||||||||
| ( L. ) Greene |
Planodes virginicum is one of only two North American plant species of the genus Planodes inthe cruciferous family (Brassicaceae). In the USA, the common names "Virginia winged rock-cress" and "Virginia-cress" are also used.
description
Vegetative characteristics
Planodes virginicum grows as an annual , herbaceous plant with stature heights of mostly 10 to 35 (5 to 55) centimeters. It forms one to several stems that are rough-haired at the base and often bald towards the top.
The basal leaves consist of a petiole and a leaf blade. The petiole has a length of usually 0.8 to 1.5 (0.3 to 2) centimeters. With a length of usually 1.5 to 7 (1 to 10) centimeters and a width of usually 4 to 20 (rarely up to 30) millimeters, the roughly elongated to obscure lanceolate leaf blade is pinnate to pinnate in detail with on each side usually 6 to 12 (4 to 15) egg-shaped or elongated to linear leaf sections. The leaf margin is often roughly serrated in the lower part of the spread and with entire or tiny serrations in the upper part of the leaf . The end section is at least the same size as the side sections, its leaf edge is entire or has a lateral tooth. The leaf surfaces are usually downy hairy, rarely they are bald.
The short stalked stem leaves have a smaller, narrower leaf blade than the basal leaves; the section margins are imperforate.
Generative characteristics
The flowering period of Planodes virginicum extends from February to April. The flowers are arranged in loose, racemose inflorescences . The straight, hairless flower stalks are usually 2.5 to 6 (1.5 to 8) millimeters long. The hermaphrodite flowers are fourfold. The four sepals 1 to 2 millimeters long and 0.5 to 0.8 millimeters wide are glabrous or not very hairy below the tip. The four white petals have a length of 2 to 3 millimeters and a width of 0.5 to 1 millimeter. The stamens are 1.5 to 2 millimeters long and the anthers measure 0.3 to 0.4 millimeters.
The bulky, spreading pods , standing on a 0.2 to 0.7 millimeter long stem, are slightly constricted and are usually 1.5 to 2.5 (1 to 3.2) centimeters long and 1 to 3 centimeters wide 1.5 millimeters. The 1 to 1.2 × 0.9 to 1 millimeter large seeds are more or less circular and have a 0.1 to 0.15 millimeter wing.
The number of chromosomes is 2n = 16.
Occurrence
Planodes virginicum is found in central, southeastern states as well as disjointly in the state of California in the USA and in the northern part of Baja California in Mexico . The spatial separation suggests that this species was introduced in the western part of the area.
Planodes virginicum inhabits floodplains, meadows, open forests, cultivated areas and ruderal areas such as rubble heaps, areas on railway tracks and dams and roadways at altitudes from 0 to 500 meters. Planodes virginicum is considered an invasive plant in some areas of North America .
Systematics
This species was in 1753 under the basionym Cardamine virginica by Linnaeus in Species Plantarum , Volume 2, page 656 first published . It was placed in 1912 by Edward Lee Greene in Leaflets of Botanical Observation and Criticism , Volume 2, p. 221 under the name Planodes virginicum in the genus Planodes . The meanwhile classifications as Arabis virginica (L.) Poir. and Sibara virginica (L.) Rollins are now to be regarded as synonyms . Other synonyms are Cardamine ludovicina Hook. , Arabis ludovicina ( Hook. ) CAMeyer and Erysimum ludovicianum ( Hook. ) Kuntze .
swell
literature
- Ihsan A. Al-Shehbaz: Planodes. In Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 7: Magnoliophyta: Salicaceae to Brassicaceae . Oxford University Press, New York / Oxford a. a. 2010, ISBN 978-0-19-531822-7 , pp. 493 (English, limited preview in Google Book search). ( Planodes virginicum - online) (section description and distribution)
Individual evidence
- ^ GRIN Taxonomy for Plants. Taxon: Planodes virginicum (L.) Greene. In: Germplasm Resources Information Network. United States Department of Agriculture - Agricultural Research Service, Beltsville Area, accessed May 30, 2011 .
- ↑ a b Plants Profile Sibara virginica (L.) Rollins. Virginia winged rockcress. In: Plants Database. NRCS Natural Resources Concervation Service - USDA United States Department of Agriculture, accessed May 30, 2011 (information on Planodes virginicum under the synonym Sibara virginica ).
- ^ Ihsan A. Al-Shehbaz: Arabis mexicana Belongs to Planodes (Brassicaceae) . In: Harvard Papers in Botany . tape 15 , no. 1 , June 2010, ISSN 1043-4534 , p. 138 , doi : 10.3100 / 025.015.0106 (English, key to and distribution of Planodes virginicum ).
Web links
- John Hilty: Virginia Rock Cress. Sibara virginica . In: Weedy Wildflowers of Illinois. Illinois Wildflowers, accessed on May 29, 2011 (English, information on Planodes virginicum under the synonym Sibara virginica ).
- Virginia winged rockcress. Sibara virginica . In: Southeastern Flora. Southeastern US Plant Identification Resource, accessed on May 29, 2011 (English, especially images from Planodes virginicum under the synonym Sibara virginica ).