Downingia pusilla

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Downingia pusilla
Systematics
Euasterids II
Order : Astern-like (Asterales)
Family : Bellflower family (Campanulaceae)
Subfamily : Lobelioideae
Genre : Downingia
Type : Downingia pusilla
Scientific name
Downingia pusilla
( G.Don ex A.DC. ) Torr.

Downingia pusilla is a species of the genus Downingia within the bellflower family(Campanulaceae). An English-speaking common name is Dwarf Calicoflower.

description

Vegetative characteristics

Downingia pusilla grows as an upright or ascending, annual , herbaceous plant that reaches heights of 3 to 15 centimeters.

The alternately arranged, early falling leaves are sitting. The simple leaf blade is elongated to linear with a length of 5 to 10 millimeters.

Generative characteristics

In California, the flowering period extends from March to May. The annual inflorescences contain several flowers. There are foliage-like bracts available. No flower stalks can be seen, so the flowers are sessile. In contrast to other Downingia species, the flowers of Downingia pusilla are not resupinate .

The very small and hermaphrodite flowers are zygomorphic and five-fold with a double flower envelope . The tubular flower cup , which looks like a flower stalk, is elongated and long. The sepals of unequal length are elongated. The five petals are fused into a two-lipped and five-lobed corolla. The corolla is white or pale blue with two yellow spots near the throat. Downingia pusilla differs from the other Downingia species that occur with it in that its flowers are much smaller with a maximum width of 2 to 4 millimeters; in other species the corollas generally have a diameter of more than 7 millimeters. The upper lip is three-lobed; these three corolla lobes are narrow-triangular with a pointed upper end. There is only one (the outer) circle with five fertile stamens . The stamens are almost completely fused and the anthers are also fused; the angle between the filament and the dust bag is less than 45 °. The two-chamber under constant ovary is bare or minimally prickly-scaly.

The two-chamber capsule fruits are 15 to 27 millimeters long and 1 to 1.2 millimeters wide, open through several longitudinal slits and contain several seeds. The seeds are spirally striped and appear twisted.

The basic chromosome number is x = 11.

Occurrence

Downingia pusilla subsp. pusilla grows in damp locations such as ditches and seasonal still waters ("vernal pools").

Systematics

The first name ( Basionym ) Clintonia pusilla , from Lobelia pusilla Poepp ex Cham. nom. nudum 1833, was given in 1834 by George Don in A General History of the Dichlamydeous Plants , 3, page 718, but without a description. The first valid description was in 1838 by Alphonse Pyrame de Candolle in Prodromus systematis naturalis , 7, page 347. The classification into the new genus Downingia was made in 1874 by John Torrey in United States Exploring Expedition , Volume 17, page 375. Another synonym for Downingia pusilla (G.Don ex A.DC.) Torr. is Bolelia pusilla (G.Don ex A.DC.) Greene .

Since 2006 there are two subspecies:

  • Downingia pusilla (G.Don ex A.DC.) Torr. subsp. pusilla : It occurs in south-central Chile and in southern Argentina .
  • Downingia pusilla subsp. humilis (Greene) Lammers (Syn .: Bolelia humilis Greene , Downingia humilis (Greene) Rattan ): This new combination and the classification as a subspecies took place in 2006. It occurs in central California and in north-central Chile.

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literature

Lisa M. Schultheis: Systematics of Downingia (Campanulaceae) Based on Molecular Sequence Data: Implications for Floral and Chromosome Evolution. In: Systematic Botany. Volume 26, No. 3, 2001, pp. 603-621. Rogers McVaugh: A Monograph on the Genus Downingia. In: Memoirs of the Torrey Botanical Club. Volume 19, No. 4, 1941, pp. 1, 3, 5-57.

Individual evidence

  1. ↑ a b c d e data sheet Downingia pusilla in NatureServe Explorer: An Online Encyclopedia of Life.
  2. ↑ a b c d e f g h i j k Lisa M. Schultheis, 2012: in Jepson Flora Project (Ed.): Jepson eFlora : Datasheet Downingia pusilla .
  3. ↑ Lisa M. Schultheis: In: Systematic Botany. Volume 26, No. 3, 2001.
  4. ^ A b Roxana Stinchfield Ferris, LeRoy Abrams: Illustrated Flora of the Pacific States. Volume IV, Stanford Univ. Press, 1960, ISBN 0-8047-0006-0 , p. 92.
  5. ↑ U. Deil: Ephemeral wetlands in a worldwide comparison with special consideration of the plant communities on the American continents. In: Reports of the Reinhold-Tüxen-Gesellschaft. Volume 17, 2005, pp. 113-135, ( digitized version ).
  6. ↑ Alphonse Pyrame de Candolle 1838: scanned into biodiversitylibrary.org .
  7. ↑ Downingia pusilla at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed May 23, 2020.
  8. ^ A b TG Lammers: Validation of Names at Subspecific Rank in North American Campanulaceae. In: Novon. Volume 16, 2006, pp. 69-73. scanned into biodiversitylibrary.org .
  9. ↑ a b Rafaël Govaerts, 2011: World checklist of selected plant families published update. - The Trustees of the Royal Botanic Gardens, Kew. Rafaël Govaerts (Ed.): Downingia pusilla. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved May 23, 2020.
  10. ↑ Data sheet with distribution map and photos at calflora.org .