Acrodon deminutus explained

Acrodon deminutus, also known as the Malgas tiptoothfig, is a species of mesemb from South Africa.

Description

This spreading succulent grows up to 10cm (00inches) tall.[1] It has a diameter of up to 40cm (20inches).[2] It has a tap root and only rarely has adventitious roots.[3] The internodes are red when young, turning ochre with age. They do not have roots and grow up to NaNmm long. The tringualar leaves are free almost to the base and grow NaNmm long and borad and 6mm thick. They are green, blue-green or grey-green in colour and have toothed margins. The keel has two or three teeth and each margin has four or five teeth. It is the only species in the genus to also have teeth over the flat sides of the leaf in some leaves. The epidermal bladder cells are completely flattened.

Single flowers are borne on the ends of branches in September. The calyx has five lobes. The bracts grow closely around the short stem holding the flower, embracing the base of the flower. The petals are magenta at the tips and bases and white in between. They have a diameter of NaNmm. The filaments holding the stamens are white at the base and magenta at the tips.

The fruit is a 5-locular capsule that has a NaNmm diameter. It is dark grey in colour. It has a flat top and shallow base with raised rimes. The closing body is lens shaped. The fruit opens through short keels becoming erect, causin the closing body to move from the base. The D-shaped seeds are brown. The testa cells are arraned in concentric rows. They are up to 1mm long and have an average mass of 20.7mg.[4]

Distribution and habitat

This species is endemic to the Western Cape of South Africa. It grows in the Renosterveld biome between Swellendam and Bredasdorp. It grows on stony quartz outcrops on clay.[5] It prefers gently sloping hills.

Etymology

The species name comes from the Latin deminutus, which means reduced or diminutive. This refers to the small size of the leaves of this species.

Conservation

This species is considered to be vulnerable by the South African National Biodiversity Institute.[6] The Swellendam area is highly cultivated, and the plants are potentially at risk of being trampled by or grazed on by livestock in the four locations that they are known from.

References

  1. e-Flora of South Africa. v1.36. 2022. South African National Biodiversity Institute. http://ipt.sanbi.org.za/iptsanbi/resource?r=flora_descriptions&v=1.36
  2. Klak . Cornelia . 2003 . New combinations, a new genus and five new species in the Aizoaceae . Bradleya . en . 21 . 21 . 107–120 . 10.25223/brad.n21.2003.a16 . 0265-086X.
  3. Hartmann . Heidrun E.K. . Niesler . Ingeborg M. . 2012 . A Gordion knot in Ruschioideae (Aizoaceae): Acrodon and Brianhuntleya in an attempt to disentangle the confusion . Bradleya . en . 30 . 30 . 33–60 . 10.25223/brad.n30.2012.a8 . 0265-086X.
  4. Schmiedel . Ute . Siemen . Svend-Erik . Dludlu . Meshack N. . Oldeland . Jens . 2021 . Germination success of habitat specialists from the Succulent Karoo and Renosterveld on different soil types . . 137 . 320–330 . 10.1016/j.sajb.2020.10.030. free .
  5. Goldblatt . P. . Manning . J. C. . Snijman . D. . 2005-08-29 . Cape plants: corrections and additions to the flora. 1 . Bothalia . 35 . 1 . 35–46 . 10.4102/abc.v35i1.367 . 2311-9284. free .
  6. Web site: Klak . C. . Helme . N.A. . Raimondo . D. . Victor . J.E. . 2005 . Acrodon deminutus Klak. National Assessment: Red List of South African Plants version 2020.1. . 22 January 2023 . SANBI Red List of South African Plants.