Leavenworthia

Leavenworthia stylosa

Leavenworthia is a genus of flowering plants in the family of cruciferous plants ( Brassicaceae). The distribution area of their eight types lies in the south and southeastern United States.

• 4.1 Notes and references

Description

Appearance and leaves

The Leavenworthia species are hairless, annual ( winter annual ) herbaceous plant with procumbent, branched stems, which sometimes may be missing.

The in basal rosettes and sometimes on the stem alternate arranged leaves are stalked. The leaf blades are simple or pinnately lobed - lyre-shaped with smooth leaf margins. The standing on the stem leaves are not auriculate at the base of the leaf.

Inflorescences and flowers

The flowers are usually singly on long Blütenstandsschäften, which grow from the basal rosettes out. Sometimes vigorous plants also form schirmtraubige inflorescences with few flowers. The inflorescence axes extend up to the fruiting of the inflorescence and later the fruit clusters are then also grapey.

The hermaphrodite flowers are cruciform. The four outstretched or slightly upright sepals are shaped oblong or oblong- linear; the lateral pair is not designed basal sack or bag- shaped. The four petals have shades in white, lavender, orange or yellow. They are much longer than the sepals. The form of the free petals ranging from obovate, spatulate, wrong - wrong - heart-shaped to lanceolate. The opposite of Kronblattplatte much shorter nail is slightly emarginate at the tip or deep, rarely truncate or obtuse. Of the six (upright) stamens have four of the same length, the other two are shorter. The stamens are not widened at their base. The oblong anthers have a blunt tip. There are both the lateral and arranged in the middle, nectar -secreting individually in a ring standing juice glands present. The ovaries are 5 to 25 ovules present. The distinctly developed, lean or squat style ends in a capitate or sometimes weakly bilobed scar.

Fruit and seeds

There are sometimes Fruchtstiele available. The smooth or beaded, rarely perlschnurartigen pods or little pods are linear to oblong or nearly spherical, with more or less circular cross-section. They are broad septate with complete septa. The Replum is rounded. The seeds are arranged in a single row. The seed coat is not slimy when wet.

Chromosome numbers

The basic chromosome number is x = 11, 12, 15

System

The genus was Leavenworthia 1837 by John Torrey in the Annals of the Lyceum of Natural History of New York, 4 ( 1 ), pp. 87-94, Table 5 with the type species Leavenworthia aurea Torr. positioned. It is named after Melines Conklin Leavenworth (1796-1862), an American physicist and botanist, who conducted collections in the Southeast, named. The genus belongs to the tribe Leavenworthia Cardamineae Dum. within the family of cruciferous plants ( Brassicaceae).

The genus contains about eight species Leavenworthia:

• Leavenworthia alabamica Rollins; is endemic of Northwest Alabama
• Leavenworthia aurea Torr.; occurs in Oklahoma and Texas
• Leavenworthia crassa Rollins; is endemic of Alabama
• Leavenworthia exigua Rollins; occurs only in Alabama, Georgia, Kentucky and Tennessee
• Leavenworthia stylosa A.Gray; is endemic of Tennessee
• Leavenworthia texana Mahler ( was texana ( Mahler ) Rollins also classified as a subspecies Leavenworthia aurea Torr var. ); is endemic to Texas.
• Leavenworthia torulosa A.Gray; occurs only in Kentucky and Tennessee
• Leavenworthia uniflora ( Michx. ) Britton; occurs only in the United States (Indiana, Ohio, Missouri, Alabama, Arkansas, Georgia, Kentucky, Tennessee).

Threats and conservation

Some Leavenworthia species are described by states in the United States as endangered.

Swell

• Ihsan A. Al - Shehbaz & James B. Beck: Magnoliophyta: Salicaceae to Brassicaceae. Brassicaceae. In: Flora of North America Editorial Committee ( eds.): Flora of North America. 7, Oxford University Press, New York, inter alia, March 14, 2010, ISBN ISBN 978-0-19-531822-7, Leavenworthia Torrey, S. 485 ( Leavenworthia - Online, accessed 23 February 2011 ). (Section Description, distribution and systematics)