Lobelia telekii

Lobelia telekii
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Campanulaceae
Subfamily: Lobelioideae
Genus: Lobelia
Species: L. telekii
Scwheinf
Binomial name
Lobelia telekii
The inflorescence of Lobelia telekii can grow up to 3 metres (10 ft) tall

Lobelia telekii is a species of flowering plant in the bellflower family, Campanulaceae, that is found only in the alpine zones of Mount Kenya, Mount Elgon, and the Aberdare Mountains of East Africa. It lives at high altitudes on well-drained sloped hillsides. It is a semelparous species, putting all its reproductive effort into producing single large inflorescence up to 3 metres (10 ft) tall, and then dying.[1]L. telekii also possesses a large pith-volume for internal water storage and marcescent foliage which could provide insulation.[2] It secretes a polysaccharide, which may be useful for its survival in the cold climate. [3] The plant is named after the Austro-Hungarian explorer, Count Sámuel Teleki.

L. telekii plants usually consist of a single rosette, which grows for several decades, flowers once, and then dies. However, a very small number of plants have multiple rosettes connected by an underground stem.[1] Each flower is subtended by a long hairy bract, and the overall appearance has led to the nickname "Cousin Itt lobelia".

The bird-pollinated flowers[4][5] of L. telekii are hidden among the large bracts within the inflorescence. The leaves and bracts are blue-green, and the flowers purple.[6] Each flower can produce up to several hundred small (<1mm diameter) dark seeds, which are passively dispersed.

On Mount Kenya, Lobelia telekii lives at elevations of 3,500–5,000 metres (11,500–16,400 ft). It inhabits the drier hill slopes, while its close relative Lobelia keniensis prefers the moister valley bottoms. Hybrids do occur. The hill slopes often have rocky moraines that are home to Mount Kenya rock hyrax, which sometimes eat lobelia leaves and inflorescences,[7] but herbivores are generally deterred by the lobelia's bitter toxic sap, which contains alkaloids, probably including lobeline.

Taxonomy

Lobelia telekii was previously classified under the Rhynchopetalum section within the Tupa subgenus. [2] The genus has since been reconfigured so that Tupa and Rhynchopetalum are separate sections, with L. telekii falling into the latter.[8] Tupa and Rhynchopetalum are separated by their difference in chromosome count and geographic distribution, supported by morphological differences.

References

  1. 1 2 Young, Truman P. (1990). "Evolution of semelparity in Mount Kenya lobelias". Evolutionary Ecology. Chapman and Hall Ltd. 4 (2): 157–171. doi:10.1007/BF02270913.
  2. 1 2 Knox, Eric B (1998). "Chloroplast DNA Evidence on the Origin and Radiation on the Giant Lobelias of Eastern Africa". Systematic Botany: 109–149.
  3. ↑ Krog, J.O. (1979). "Thermal buffering in afro-alpine plants due to nucleating agent-induced water freezing". Nature. 282: 300–301. doi:10.1038/282300a0.
  4. ↑ Young, Truman P. (1982). "Bird visitation, seed set, and germination rates in two species of Lobelia on Mount Kenya". Ecology. 68: 1983–1986. doi:10.2307/1940139.
  5. ↑ Smith, Alan P.; Truman P. Young (1987). "Tropical Alpine Plant Ecology". Annual Review of Ecology and Systematics. 18 (1): 137–158. doi:10.1146/annurev.es.18.110187.001033.
  6. ↑ Mabberley, D. J. (1975). "The Giant Lobelias: Pachycauly, biogeography, ornithophily and continental drift". New Phytologist. 74 (2): 365–374. doi:10.1111/j.1469-8137.1975.tb02623.x.
  7. ↑ Young, Truman P. (1984). "The comparative demography of semelparous Lobelia telekii and iteroparous Lobelia keniensis on Mount Kenya". Journal of Ecology. 72 (2): 637–650. doi:10.2307/2260073. JSTOR 2260073.
  8. ↑ Lammers, Thomas (2011). "Revision of the Infrageneric Classification of Lobelia L. (Campanulaceae: Lobelioideae)". Annals of the Missouri Botanical Garden. 98: 37–62. doi:10.3417/2007150.


This article is issued from Wikipedia - version of the 9/3/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.