Sphenoclea zeylanica

from Wikipedia, the free encyclopedia
Sphenoclea zeylanica
Sphenoclea zeylanica, infructescence and deciduous leaves

Sphenoclea zeylanica , infructescence and deciduous leaves

Systematics
Asterids
Euasterids I
Order : Nightshade (Solanales)
Family : Sphenocleaceae
Genre : Sphenoclea
Type : Sphenoclea zeylanica
Scientific name of the  family
Sphenocleaceae
T.Baskerv.
Scientific name of the  genus
Sphenoclea
Garden.
Scientific name of the  species
Sphenoclea zeylanica
Garden.

Sphenoclea zeylanica is the only species of the genus Sphenoclea and the plant family Sphenocleaceae . According to current knowledge, it is classified in the order of the nightshade-like (Solanales). It originally comes from Africa, but is now naturalized in many parts of the world. Since it has similar habitat requirements as rice and inhibits the growth of rice plants, this plant species is an important weed in rice cultivation. Sometimes it is used as a vegetable .

description

Vegetative characteristics

Sphenoclea zeylanica grows as an annual herbaceous plant and reaches stature heights of usually 0.5 to 0.7 meters (rarely 0.2 to 1.5 meters.) It particularly thrives in damp and flooded areas. All parts of the plant are bare. The numerous roots are long and cord-like. The upright, mostly strongly branched stems are fleshy and more or less hollow with a diameter of up to 1 centimeter.

The alternate arranged on the stem leaves are long stalks to 2.0 centimeters to 0.5. The simple leaf blade is egg-shaped to elliptical with a length of 6 to 12 centimeters and a width of mostly 2 to 3.5 (rarely also up to 6) centimeters; In the Flora of China 2011 one finds the following information about the leaf blade: with a length of 2 to 9 centimeters and a width of 0.5 to 2 cm it is long-elliptical, elliptical-lanceolate or ovoid-lanceolate. The tip of the leaf can be blunt, but also pointed to prickly, while the base of the leaf is usually wedge-shaped and the edge of the leaf is smooth. The underside of the leaf is gray to green and the upper side is green.

Inflorescences and flowers

The inflorescences are terminal on the main axes on 1.5 to 5.0 (rarely up to 10.0) centimeter long inflorescence shafts. With a length of 2.5 to 8.0 ( Flora of China : 1 to 4) centimeters and a diameter of 6.0 to 9.0 centimeters, the cylindrical, spiked inflorescences are densely populated with up to 100 flowers. The inflorescences contained spatula-shaped or ovoid, 2.0 to 3.0 millimeters long support leaves (bracts) with pointed tip to blade tips. The bracteoles are paired, broadly linear, irregularly serrated at the tip and also 2.0 to 3.0 millimeters long.

The seated flowers are smaller than 2 millimeters, radial symmetry and five-fold with a double flower envelope . The flower cup (hypanthium) is compressed along its length, at the base it is broadly fused with the inflorescence axis, and when old it is weakly cartilaginous. The five calyx lobes are ovate-circular or broad and obtuse triangular to almost rounded and 1.5 to 2.5 millimeters long. By the time the fruit is ripe, the calyx becomes a little narrower and is then further rounded and provided with an irregularly jagged to paper-like tip that is curved and conceals the tip of the fruit. The five white and about 2.5 millimeter long petals are fused to about half of their length to form a 1.0 to 1.5 millimeter long corolla tube. The overlapping crown lobes are obtuse triangular and 1.0 to 1.2 millimeters long. There is only one circle with five stamens . The thread-like stamens are very short with a length of 0.4 millimeters and arise at or slightly below the center of the corolla tube. The anthers are almost circular with a length of 0.5 millimeters. The more or less continuous, two-chamber ovary is at a length of about 2.5 millimeters obovate with trimmed upper end. Each ovary contains many anatropic ovules in a central-angled placentation. The scar is inconspicuously bilobed, almost head-shaped. Sphenoclea zeylanica blooms all year round and only a few flowers of an inflorescence are open at the same time.

Fruits and seeds

The capsule fruits , which stand close together in the fruit stands and spring up in a circle, have a length of 2.5 to 3.0 millimeters and a diameter of 2 to 4 millimeters. The fruits contain many seeds. The pale yellowish-brown or brown-yellow, shiny seeds are elongated-cylindrical with a length of 0.5 millimeters, striped lengthways with ten to twelve grooves, slightly and indistinctly grained between the grooves. The fruits ripen all year round.

The number of chromosomes is 2n = 32 or 48.

Sphenoclea zeylanica

Occurrence and locations

The original distribution area of Sphenoclea zeylanica is in tropical to southern Africa : Kenya , Tanzania , Uganda , Gambia , Ghana , Guinea , Mali , Senegal , Sierra Leone , Malawi , Mozambique , Zambia , Botswana and Madagascar . Today it is also widespread in tropical Asia, on the Pacific islands and in the Neotropics as a presumably introduced plant.

Sphenoclea zeylanica prefers moist locations at low altitudes, it is often found in rice fields and swamps that have been flooded for a long time. In Nepal it also grows at altitudes of up to 1,600 meters.

Botanical history and systematics

Historical illustration by Francisco Manuel Blanco

Sphenoclea zeylanica and the genus Sphenoclea were 1788 by Joseph gardener in De fructibus et Seminibus Plantarum .... , 1, p 113, Table 24, Figure 5 first described . Synonyms for Sphenoclea Gaertn. are: Gaertnera Retz. (non Gaertnera Schreber , non Gaertnera Lam. ), Pongati Adans. , Pongatium Juss. and Rapinia Lour. Synonyms for Sphenoclea zeylanica Gaertn. are: Gaertnera pangati Retz. , Pongatium indicum Lam. , Pongatium indicum Lam. , Pongatium spongiosum Blanco , Pongatium zeylanicum (Gaertn.) Kuntze , Rapinia herbacea Lour. , Reichelia palustris Blanco , Sphenoclea dalzielii N.E.Br. , Sphenoclea pongatia A.DC. , Sphenoclea pongatium A.DC.

The Sphenocleaceae family was established in 1839 by Thomas Baskerville in Affinities of Plants: With Some Progressive Development , p. 110. A synonym for Sphenocleaceae is Pongatiaceae Engl. Ex Meisn. nom. illegal.

Sphenoclea zeylanica is the only species of the genus Sphenoclea and the Sphenocleaceae family today . Some authors also mention that there are one or two other types, but these are only synonyms.

The family of the Sphenocleaceae is classified in the order of the nightshade-like (Solanales) based on current molecular biological studies . Previously, based on morphological studies , this family was mostly classified into the order of the aster-like (Asterales) or the order of the bellflower-like (Campanulales). There she was typically near or in the family Bellflower Family placed (Campanulaceae). Against this classification, the fact that there is no milky sap in the genus Sphenoclea , on the other hand, is typical for the bluebell family. Further features that distinguish the Sphenocleaceae from the aster-like or from the bellflower-like are the scale-shaped corolla lobes, the tetracytric stomata and the ring-shaped popped capsule fruits. Herbert Kenneth Airy Shaw had already questioned this classification of the family in 1948 , but his statements in this regard were not accepted. He saw the family placed near the pokeweed family (Phytolaccaceae).

The relationships to the rest of the nightshade families (Solanales) are shown in the following cladogram according to Cosner 1994:

 Solanales 



Hydroleaceae


   

Sphenocleaceae



   

Montiniaceae



   

Solanaceae


   

Convolvulaceae




Template: Klade / Maintenance / Style

Weeds and ecology

Sphenoclea zeylanica is a weed in rice cultivation , especially in Southeast Asia , the USA , the Caribbean , India , Pakistan and West Africa . There are also reports of the occurrence of Sphenoclea zylanica in cotton plantings, as well as in wheat and soybeans that are grown with rice in alternating cultures . Sphenoclea zeylanica can reduce the harvest yield by up to 45%.

However, other studies also show a possible positive effect of Sphenoclea zeylanica : It has been proven that substances excreted by the species are the rice root nematodes Hirschmanniella spp. - another important rice pest - can be reduced by up to 99%.

Various herbicides are used to counteract the impairment of crops by Sphenoclea zeylanica , including 2,4-D , butachlor and mecoprop . However, plants from the Philippines are known that have developed a tolerance to 2,4-D. Molds from the genus Alternaria can be used as biological alternatives to weed control , but experiments have shown that the use of 2,4-D is more effective.

Vegetable plant

In some cases, young Sphenoclea zeylanica plants are used as vegetables ; when steamed they have a piquant, slightly bitter taste. Taiwanese rice farmers sell the plants as vegetables, some farmers even cultivate Sphenoclea zeylanica specifically.

proof

literature

Individual evidence

Most of the information in this article has been taken from the sources given under literature; the following sources are also cited:

  1. ↑ a b c d e f g h i j k l m n o p q Deyuan Hong & Nicholas J. Turland: Sphenocleaceae . In: Flora of China Editorial Committee: Wu Zheng-yi, Peter H. Raven & Deyuan Hong (Eds.): Flora of China . Cucurbitaceae through Valerianaceae, with Annonaceae and Berberidaceae. Volume 19. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2011, ISBN 978-1-935641-04-9 , pp. 504 (English, family Sphenocleaceae , genus Sphenoclea and species Sphenoclea zeylanica - online - online text is identical to the printed work; text is identical to the printed work full-text online).
  2. ↑ Mats Thulin: Sphenoclea zeylanica  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. @1@ 2Template: Dead Link / www.aluka.org   . In: HK Airy Shaw (ed.) Flora of Tropical East Africa: Campanulaceae , Crown Agents, 1976.
  3. ↑ a b c d e S. MH Jafri: Sphenocleaceae entry in the Flora of Pakistan , University of Karachi.
  4. ↑ Sphenoclea zeylanica at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
  5. ↑ a b c Sphenocleaceae T. Baskerv., Nom. cons. at GRIN. Retrieved November 7, 2011.
  6. ↑ Sphenoclea zeylanica Gaertn., Sphenocleaceae - data sheet at Pacific Island Ecosystems at Risk = PIER. Online, accessed June 26, 2007.
  7. ^ Blanca Leon and Kenneth R. Young: Aquatic plants of Peru: diversity, distribution and conservation . In: Biodiversity and Conservation , Volume 5, Issue 10, October 1996. Pages 1169–1190. doi: 10.1007 / BF00051570
  8. ^ WH Reissig et al .: Illustrated guide to integrated pest management in rice in tropical Asia , International Rice Research Institute, 19856. ISBN 978-971-10-4120-5 . Pp. 300-301.
  9. ↑ Sanjay Manandhar: Plants and People of Nepal , Timber Press, 2002. ISBN 978-0-88192-527-2 . P. 437
  10. ↑ Entry Sphenoclea zeylanica at IPNI
  11. ↑ Sphenocleaceae T. Baskerv. at Tropicos . Retrieved November 7, 2011.
  12. ↑ The family of Sphenocleaceae in APWebsite. Retrieved November 6, 2011.
  13. ^ A b Mary E. Cosner, Robert K. Jansen and Thomas G. Lammers: Phylogenetic relationships in the Campanulales based on rbcL sequences. In: Plant Systematics and Evolution , Volume 190, Numbers 1-2, March 1994. Springer Verlag Vienna. Pages 79-94. doi: 10.1007 / BF00937860
  14. ↑ Rhomela F. Masangkay et al .: Factors Influencing Biological Control of Sphenoclea zeylanica with Alternaria alternata f. sp. sphenocleae. In: Plant Disease , Volume 83, Number 11, November 1999, pages 1019-1024. doi: 10.1094 / PDIS.1999.83.11.1025
  15. ↑ Michel Luc, Richard A. Sikora, John Bridge: Plant parasitic nematodes in subtropical and tropical agriculture , CABI, 2005. ISBN 978-0-85199-727-8 . P. 109.
  16. ^ JT Swarbrick and JH Kent: The Status of Weed Control in Tropical Pastures . In: Improving Weed Management , Food and Agriculture Organization of the United Nations, International Weed Science Society, 1982. pp. 126-135
  17. ↑ BL Mercardo et al .: Growth behavior and leaf morphology of Philippine strains of Sphenoclea zeylanica showing differential response to 2,4-D . In: Weed Research , Volume 20, Number 4, 1990. pp. 245-250. doi: 10.1111 / j.1365-3180.1990.tb01710.x
  18. ↑ MO Mabbayad and AK Watson: (. Sphenoclea zeylanica Gaertn) Biological control of gooseweed with sp to Alternaria. In: Crop Protection , Volume 14, Issue 5, August 1995, pp. 429-433. doi: 10.1016 / 0261-2194 (95) 00015-E
  19. ↑ Monica L. Naples and Paul JA Kessler: Weeds of Rain Fed Lowland Rice Fields of Laos & Cambodia. ( Memento of the original from September 29, 2007 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. Unpublished MSc thesis, University of Leiden, The Netherlands.  @1@ 2Template: Webachiv / IABot / www.nationaalherbarium.nl

Web links

Commons : Sphenoclea zeylanica  - collection of images, videos and audio files
This version was added to the list of articles worth reading on September 5, 2009 .