Purslane (genus)

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Purslane
Portulaca villosa

Portulaca villosa

Systematics
Class : Bedecktsamer (Magnoliopsida)
Eudicotyledons
Nuclear eudicotyledons
Order : Clove-like (Caryophyllales)
Family : Purslane family
Genre : Purslane
Scientific name of the  family
Portulacaceae
Yuss.
Scientific name of the  genus
Portulaca
L.

Purslane ( Portulaca ) is the only plant genus of the purslane family (Portulacaceae) in the order of the carnation-like (Caryophyllales) within the flowering plants .

description

Illustration of the summer purslane ( Portulaca oleracea )

Portulaca species grow as annual or perennial herbaceous plants . Many species are succulent due to thickened leaves, thickened shoot axes or storage roots . The stems are erect to creeping. Most of the annual species are tender and tiny.

The leaves are mostly alternate , rarely arranged opposite. The simple, sessile leaves are flat to stalk-round, often fleshy and almost always with entire margins. Stipules are mostly absent; if they are present, they form axillary hairs.

The often terminal, zymose or, more rarely, paniculate inflorescences contain one to 30 flowers and bracts . The sessile flowers are usually large and conspicuous, but short-lived and often cleistogamous . Almost all species are hermaphroditic . Single-sex flowers occur only very rarely and then the species are dioecious separately sexed ( diocesan ). The sepals are probably not genuine, but shifted, modified bracts (bracts), while the petals shifted sepals represent and missing real petals. There are usually many (rarely only four, usually six to 40, rarely up to 100) stamens present. The ovary is subordinate or semi-subordinate. In many species, the flowers only open when the sun is shining, which is why they are called ice flowers like many other species of different genera.

They form capsule fruits that open in cross section and contain many seeds. The tiny seeds are rarely brown, mostly iridescent gray to shiny black and spherical to kidney-shaped.

The chromosome numbers are n = 4, 5, 8, 9.

distribution

The purslane family is widespread all over the world , with the exception of the polar regions . Their main area of ​​distribution is in the southern hemisphere . They mostly thrive in arid tropical and subtropical areas. Main areas of distribution are in Africa and South America. Only a few species inhabit temperate areas.

Systematics

External system

Portulaca amilis
Portulaca confertifolia
Portulaca conspicua
Portulaca elatior
Portulaca eruca
Portulaca filifolia
Portulaca gilliesii
Semi-double-flowered variety of Portulaca grandiflora
Portulaca lutea
Portulaca molokiniensis
Portulaca mucronulata
Portulaca mundula
Summer purslane ( Portulaca oleracea )
Portulaca pilosa
Portulaca umbraticola
Portulaca werdermannii

DNA analyzes carried out in recent years have confirmed the long-held assumption that the purslane family does not form a uniform, monophyletic family, but that they are markedly paraphyletic . Because of the great variability of plants, morphological characteristics and even the flower characteristics that are otherwise regarded as “conservative” are not a reliable means of distinguishing between genera and species. As a result, only the genus Portulaca remains in the family today. The vast majority of the genera previously classified here are now part of the Montiaceae family .

Very closely related to the Portulacaceae s. st. are the cactus family (Cactaceae), Anacampserotaceae and Talinaceae . The latest research suggests that these are even nested within the purslane family. If the cacti were to be preserved as an independent family, the purslane family would have to be divided into at least two separate families. Either you leave the Portulacaceae s. l. as a paraphyletic family or - if only monophyletic taxa are allowed - there are monogeneric families like Portulacaceae s. str., Anacampserotaceae and Talinaceae.

Also relatively closely related are the Halophytaceae , Didiereaceae , Basellaceae and Montiaceae , which are in a clade . According to the latest research results, it is proposed to include the previous genera of the purslane family Calyptrotheca , Ceraria and Portulacaria among the Didiereaceae.

Internal system

The first scientific description of the genus Portulaca was in 1753 by Carl von Linné in his work Species Plantarum . The surname Portulacaceae was published in 1789 by Antoine Laurent de Jussieu in Genera Plantarum . The type species is Portulaca oleracea L. Synonyms of the genus are Lemia Vand. (1788), Merida Neck. (1790), Portulacca Haw. (1812, nom. Invalid ICBN -Article 61.1), Lamia Endl. (1839) and Sedopsis (Endl.) Exell & Mendonca (1937).

The genus Portulaca includes the following species:

swell

literature

  • R. Matthew Ogburn & Erika J. Edwards: Anatomical variation in Cactaceae and relatives: Trait lability and evolutionary innovation. , in American Journal of Botany , 96, 2009, pp. 391-408.
  • Roger Charles Carolin: A review of the family Portulacaceae , in Taxon , 23, 1974, pp. 725-728.
  • J. Jage: 47. Family: Portulacaceae , in Illustrierte Flora von Mitteleuropa , 2nd edition, 3 (2), 1979, pp. 1183-1221.
  • Roger Charles Carolin: Notas sobre Portulacaceae de la Argentinia , in Parodiana 3 (2), 1987, pp. 329-332.
  • BL Nyananyo: The systematic significance of seed morphology and anatomy in the Portulacaceae (Centrospermae) , in Folia Geobot. Phytotax. , 23, 1988, pp. 275-79 & plates 8-13.
  • M. Prabhakar, P. Leelavathi, & BKV Kumar: SEM studies on seeds of Indian Portulacaceae and their taxonomic significance , in Asian J. Pl. Sci. 2, 1990, pp. 9-14.
  • Roger Charles Carolin: A review of the family Portulacaceae , in Austral. Journ. Bot. , 35 (4), 1993, 383-412.
  • LI Malyschev & GA Peschkova (eds.): Portulacaceae - Ranunculaceae , in Flora of Siberia Series Volume 6, 2003.
  • Lonnie J. Guralnick, Michael D. Jackson: The Occurrence and Phylogenetics of Crassulacean Acid Metabolism in the Portulacaceae . In: International Journal of Plant Sciences . Volume 162, Number 2, 2001, pp. 257-262, DOI: 10.1086 / 319569 .
  • BL Nyanannyo, SI Mensah: Distribution and origins of members of the Family Portulacaceae (Centrospermae) . In: Journal of Applied Sciences & Environmental Management , Volume 8, Number 2, 2004, pp. 59-62.

Individual evidence

  1. ↑ Basal cactus phylogeny: implications of Pereskia (Cactaceae) paraphyly for the transition to the cactus life form [1]
  2. ↑ Reto Nyffeler: The closest relatives of cacti: insights from phylogenetic analyzes of chloroplast and mitochondrial sequences with special emphasis on relationships in the tribe Anacampseroteae , in American Journal of Botany , 94, 2007, pp. 89-101 .: Online.
  3. ↑ Wendy L. Applequist & Robert S. Wallace: Expanded circumscription of Didiereaceae and its division into three subfamilies , in Adansonia , sér. 3, 25 (1), 2003: pdf-Online. ( Memento of the original from November 19, 2006 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.mnhn.fr
  4. ↑ Carl von Linné: Species Plantarum . 1st edition, Lars Salvius, Stockholm 1753, pp. 445-446 (online) .
  5. ↑ Genera Plantarum, secundum ordines naturales disposita juxta methodum in Horto Regio Parisiensi exaratam . Paris 1789, p. 312 (online) .
  6. ↑ Urs Eggli: Portulaca . In: Urs Eggli (Hrsg.): Succulent lexicon . Volume 2, Dicotyledons, Eugen Ulmer, Stuttgart 2002, ISBN 3-8001-3915-4 , p. 428.
  7. ↑ Urs Eggli: Portulaca . In: Urs Eggli (Hrsg.): Succulent lexicon . Volume 2, Dicotyledons (Dicotyledons), Eugen Ulmer, Stuttgart 2002, ISBN 3-8001-3915-4 , pp. 430-433.
  8. ↑ a b c d e f g h i j k Portulaca in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved September 20, 2017.

Web links

Commons : Purslane ( Portulaca )  - Collection of images, videos and audio files