Agavoideae
Dragon Tree Agave ( Agave attenuata )
The agave ( Agavoideae ) are a subfamily of the family of asparagus plants ( Asparagaceae ) within the order of asparagus -like ( Asparagales ). Some species are grown as ornamental plants in parks, gardens and rooms. From the few species further use by humans is well known: from the sap of some species of agave, pulque is made and the fibers of some agave and yucca species are processed.
- 5.1 Notes and references
Description
Vegetative characteristics
There are perennial or perennial plants, there are herbaceous to shrub-like or even tree- growing species; they form rhizomes. Few species are epiphytes. Many species are evergreen. Many species are succulents, so they can save water. Agave and Yucca are CAM plants. The Stems often do not extend over the soil surface, but when do species form in many years simple or branched stems from. The leaves are alternate and spiral, and usually arranged in rosette. The leaves are always simple and parallel-veined ( never annoying network ). In many species the leaves are reinforced in the margin. The stomata are anomocytisch.
Generative features
They often bloom only in old age, with some species die off after the formation of seeds, so are monokarp ( Hapaxanthe plants), but most species are Polycarp. Often, simple or branched, racemose inflorescences are floriferous. There are two or more bracts present, but the inflorescence never completely envelop ( delimitation of Asparagaceae to other families of the order ). The threefold flowers are usually hermaphrodite, or functionally unisexual rare. There are two circles with more or less the same multiform bloom cladding available; they are often free, but can also be fused into a tube. There are two circles, each with three fertile stamens present, the project beyond the perianth or not. The three carpels are fused. The Nektatsekretion done in Septalnektarien.
They usually form capsule fruits, some yucca species produce berries. You seeds are usually flat and contain no starch. The endosperm is helobial and oily.
The chromosome numbers often be n = 24, 30 For example, Leucocrinum montanum with basic chromosome numbers of n = 11, 13, 14 or Echeandia n = 8 diverge from it.
Ingredients
In many taxa saponins are detected.
Dissemination
The subfamily of Agavoideae has an almost worldwide distribution. The focus of biodiversity lies in the Neotropics. The natural areas of many ranging from the southern United States via Central America to northern South America and Asia. In each case, some species occur, for example, in Malaysia's, northern Australia and New Zealand and the Caribbean Islands. In addition, there are taxa in tropical to subtropical regions of other continents and some taxa is also available in the Holarctic. By the people came, some American species as well as to southern Europe and in other regions of the earth. Most species do not tolerate frost.
System
The subfamily was erected in 1837 by William Herbert as " Agaveae ". Type genus Agave L.
2006 executed by David John Bogler, Joseph Christopher Pires and Javier Francisco - Ortega molecular genetic studies revealed the following relationships:
Agave S. L.
Furcraea
Yucca
Hesperoyucca
Chlorogalum
Hosta
Hesperocallis
Echeandia
Leucocrinum
Behnia
Anemarrhena
The scope of some species has been heavily modified by revisions in the last ten years. Today, there are 18 genera with about 600 species in the subfamily of the agave ( Agavoideae ):
- Agave ( Agave L.). Including the former genera Manfreda Salisb, night hyacinths ( Polianthes L.), Prochnyanthes S.Watson, Pseudobravoa rose with about 210 species from the southern United States via Mexico throughout Central America and the Caribbean Islands to northern South America.
- Anemarrhena Bunge, with only one type: Anemarrhena asphodeloides Bunge: It is native to northern China and Korea.
- Behnia reticulata ( Thunb. ) DITR. It is located in southeastern Africa.
- Herreriopsis elegans H.Perrier: It is native to Madagascar.
- Hesperocallis undulata A. Gray: It is native to the southwestern United States.
- Leucocrinum montanum Nuttall ex A. Gray: It is native to the western United States.
Synonyms for Agavoideae Herb. are: Agavaceae Dum, Anthericaceae J.Agardh, Anemarrhenaceae Conran, MWChase & Rudall, Behniaceae Conran, MWChase & Rudall, Chlorogalaceae Doweld & Reveal, Funkiaceae Horan, Herreriaceae Kunth, Hesperocallidaceae Traub, Hostaceae B.Mathew and Yuccaceae J. .. . Agardh.
Botanical history
Molecular genetic studies have led over the past ten years, to the family boundaries within the order of asparagus -like ( Asparagales ) have dramatically shifted. Thus, the century plants are now only a subfamily ( Agavoideae ) in the family of asparagus plants ( Asparagaceae ). Previously it was an independent family Agavaceae. The genera were formerly in the Liliaceae Juss. incorporated. The Agavaceae family was first described as Agavineae 1829 by Barthélemy Charles Joseph Dumortier in analysis of Familles de Plantes 57, 58.
Swell
- The subfamily Agavoideae in APWebsite. ( Section systematics and description) viewed in January 2010
- Susan Verhoek, William J. Hess: Agavaceae in the Flora of North America, Volume 26, 2002, p 413: Online. ( Description section ) viewed in January 2010
- The Agavaceae family, the family of Anemarrhenaceae, Anthericaceae, Behniacaceae and Herreriaceae at DELTA by L. Watson & MJ Dallwitz. ( Description section ) viewed in January 2010
- DJ Bogler, BB Simpson: A chloroplast DNA study of the Agavaceae. In: Systematic Botany. Volume 20, 1995, pp. 191-205 ( doi: 10.2307/2419449 ).
- DJ Bogler, BB Simpson: Phylogeny of Agavaceae based on ITS rDNA sequence variation. In: American Journal of Botany. Volume 83, 1996, pp. 1225-1235 ( doi: 10.2307/2446206 ).
- DJ Bogler, JC Pires, J. Francisco - Ortega: Phylogeny of Agavaceae based on ndhF, rbcL, and ITS sequences: Implications of molecular data for classification. In: JT Columbus, EA Friar, JM Porter, LM Prince, MG Simpson ( eds.): Monocots: Comparative Biology and Evolution. Excluding Poales. In: Aliso. Volume 22, 2006, pp. 313-328.