Cotyledon orbiculata

Source: Wikipedia, the free encyclopedia.

xu kai plant
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Crassulaceae
Genus: Cotyledon
Species:
C. orbiculata
Binomial name
Cotyledon orbiculata
approximate native range
Synonyms

Cotyledon elata Haw.
Cotyledon ovata Haw.
Cotyledon ramosa Haw.
Cotyledon oblonga Haw.
= C. o. var. oblonga (Haw.) DC.

Cotyledon orbiculata, commonly known as pig's ear or round-leafed navel-wort, is a South African succulent plant belonging to the genus Cotyledon.

Description

Cotyledon orbiculata is an extremely variable species, one that grows to approximately 1.3 m (4.3 ft) in height.[1] It has gray-green leaves (up to 13 by 7 cm (5.1 by 2.8 in)), which naturally develop a white, powdery substance (known as farina) on their surfaces; this farina helps reflect sunlight and conserve water. If a specific leaf area is brushed against (or even gently disturbed), the farina will noticeably become smudged. While this powder does not regenerate when disturbed or wiped off, this is normally not detrimental and very rarely unsightly. The majority of succulent plants will, ultimately, lose and replace their older leaves with time. Ironically, water (as dew, marine layer/fog, mist, rain, or even garden hose or hand-watering), does not seem to wash the farina off, and it reappears again as the leaves are drying.[2] The shape of the leaves was thought to have a resemblance to a pig's ear, thus the common name.[3]

The bell-shaped flowers, which appear in winter, are usually a blood orange-red or a paler salmon-orange; yellow varieties also exist. To the untrained eye, the blossoms may resemble the blooms of the distantly-related

corolla (2 per petal), and the 5 carpels
each have a style longer than the ovary.

  • Flower
    Flower
  • Yellow form
    Yellow form
  • Leaves (green variety)
    Leaves (green variety)
  • Grey variety in cultivation
    Grey variety in cultivation

Varieties and cultivars

This diverse species includes a large number of hybrids and cultivated forms, some of which may show a distinct resemblance to Kalanchoe thyrsiflora or K. luciae.[4][5]

Recognised varieties include:

  • Cotyledon orbiculata var. flanaganii (Schönl. & Baker f.) Toelken ― with elongated leaves in whorls
  • Cotyledon orbiculata var. oblonga (Haw.) DC. ― defined by its red leaf-margins and 20–50 cm inflorescence
  • Cotyledon orbiculata var. spuria (L.) Toelken ― defined by having (2–)3–5 bract pairs on the stem of its inflorescence

Other forms include:

  • Cotyledon orbiculata var. dactylopsis ― small and proliferous plant with elongated, terete leaves
  • Cotyledon orbiculata var. engleri (= cultivar: "Viridis") ― leaves a deep and slightly glaucous green
  • Cotyledon orbiculata var. mucronata ― defined by its
    mucronate
    leaves
  • Cotyledon orbiculata var. oophylla Dinter (= cultivars: "Boegoeberg" and "Lizard Eggs") ― defined by its round, white,
    pruinose
    leaves
  • Cotyledon orbiculata var. undulata Haw. (= cultivar: "Silver Crown") ― defined by its wide, flat, round leaves with bent margin
  • Cotyledon orbiculata f. takbok ― leaves often with multiple lobes, becoming antler-like
  • Cotyledon orbiculata is a common garden plant, with many different varieties. The antler-like leaves of the takbok form can be seen on the left for example.
    Cotyledon orbiculata is a common garden plant, with many different varieties. The antler-like leaves of the takbok form can be seen on the left for example.
  • Var. engleri, with its deep glaucous-green leaves
    Var. engleri, with its deep glaucous-green leaves
  • Var. flanaganii often has its elongated leaves in whorls of three.
    Var. flanaganii often has its elongated leaves in whorls of three.
  • Var. oblonga, a cultivar known as "Grey Sticks"
    Var. oblonga, a cultivar known as "Grey Sticks"
  • Var. oophylla has round, white, pruinose leaves.
    Var. oophylla has round, white, pruinose leaves.
  • "Shireen" form
    "Shireen" form
  • Var. spuria
    Var. spuria

Distribution

Native to South Africa,[1] it is popular in gardens in many countries. In the wild, it grows naturally in rocky outcrops in grassy shrubland and the Karoo region. In New Zealand, it is considered an invasive plant and is listed on the National Pest Plant Accord.[6]

Uses

Cotyledon orbiculata has a number of

vermifuge and the juice has been used to treat epilepsy.[2]

However, the leaves contain a bufanolide called cotyledontoxin, which is toxic to sheep, goats, horses, cattle, poultry, and dogs, causing a condition known as cotyledonosis.[7]

References

  1. ^ a b c "Cotyledon orbiculata". University of Oklahoma Department of Botany & Microbiology. June 13, 2009. Archived from the original on 2010-10-16. Retrieved 2010-04-19.
  2. ^ a b Harris, Shireen. "Cotyledon orbiculata". South Africa National Biodiversity Institute. Retrieved 2010-04-19.
  3. ISBN 978-1-77007-490-3
    .
  4. ^ Cotyledon orbiculata PlantZAfrica.com
  5. ^ H. R. Tölken (1985). Crassulaceae. In O. A. Leistner, Flora of southern Africa 14. Botanical Research Institute, Pretoria.
  6. ^ "National Pest Plant Accord" (PDF). Ministry of Agriculture and Forestry. 2008. Archived from the original (PDF) on 2008-10-15. Retrieved 2010-04-19.
  7. ISBN 3-540-52171-2
    .

External links

Wikimedia Commons has media related to Cotyledon orbiculata.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Cotyledon_orbiculata&oldid=1191688766"