Mesembryanthemoideae

Mesembryanthemoideae
Mesembryanthemum nodiflorum
Systematics
Class : Bedecktsamer (Magnoliopsida) Eudicotyledons Nuclear eudicotyledons Order : Clove-like (Caryophyllales) Family : Midday flowers (Aizoaceae) Subfamily : Mesembryanthemoideae
Scientific name
Mesembryanthemoideae
Ihlenf. , Schwantes & Straka

The Mesembryanthemoideae are a subfamily of the ice plant family (Aizoaceae) within the order of the carnation-like (Caryophyllales).

description

Vegetative characteristics

The members of the subfamily Mesembryanthemoideae are annual or biennial herbaceous plants , small to large shrubs or geophytes . They grow lying, prostrate or upright, sometimes tufted and only rarely creeping. Their roots are sometimes thickened. The internodes are herbaceous, woody or succulent . They are either green and assimilating or distinctly corky . The internodes are round, angular or winged and usually contain additional vascular bundles in their bark . Their flat to (almost) cylindrical or slightly trough-shaped leaves sit opposite to one another and often become alternate when the inflorescence is formed or they are continuously alternate. Cross-opposed leaves are usually briefly fused together at their base. The leaves are persistent, withering or sloping. Cylindrical leaves often contain enlarged central water-storing cells. The bladder cells in the epidermis are large to severely flattened and then appear to be absent. They are mostly mesomorphic, but sometimes also xeromorphic.

Inflorescences and flowers

The flowers appear singly or in a zymous inflorescence and reach a diameter of 10 to 60 millimeters. There are four to five sepals available. The pink, salmon-colored, orange, yellow, cream-colored, sand-colored, greenish or white petals are usually fused with the sepals to form a short or long tube. However, sometimes they are free at their base. The petals are thread-like or narrowly lanceolate and rarely strongly receded. Thread-like staminodes may be present or absent. The stamens are smooth and have no papillae . The petals often go into thread-like staminodes and stamens. Sometimes the reproductive organs are hidden by the thread-like staminodes or the inner petals. The four or five separate nectaries are shell or tube-shaped and only rarely receded. The medium-sized to upper permanent ovary is septate and contains a central angle constant ovules .

Fruits and seeds

The fruits are columnar , hygrochastic capsule fruits or are rarely nut-like . They open and close with the help of source bars. The fruits usually have flap wings that can be bent upwards or downwards and are fused together in pairs. The valve wings are rarely missing. The fruits are four- or five-compartment and only rarely tripple. They contain broad or narrow egg-shaped, triangular, D-shaped, kidney-shaped or pear-shaped seeds . The black, brown, yellow or whitish seeds have a smooth or rough seed coat with or without a clear rim.

cytology

The basic chromosome number is x = 9.

distribution

The subfamily Mesembryanthemoideae is found in southwest Angola , southwest Australia , the Azores , the Canary Islands , the Cape Verde Islands , Iraq , Iran , Mauritania , the Mediterranean , Namibia , North Africa, Palestine , St. Helena , distributed in Turkey , California and the South African provinces of Eastern Cape , Free State , North Cape and Western Cape . The species usually grow in disturbed places, mainly in winter rain areas , but some species also in summer rain areas .

Systematics

External system

The Mesembryanthemoideae are one of the four subfamilies of the ice plant family (Aizoaceae) within the order of the carnation-like (Caryophyllales). The subfamily differs from the other subfamilies by hollow, shell-shaped (koilomorph) nectaries .

Internal system

The subfamily was first recognized by Gustav Schwantes in 1947 under the name Aptenioideae. However, in the absence of a Latin diagnosis, the name was invalidly published according to the rules of the International Code of Botanical Nomenclature . A Latin diagnosis was published in 1962 by Hans-Dieter Ihlenfeldt (* 1932), Gustav Schwantes and Herbert Straka (1920–2009) under the new name Mesembryanthemoideae. The type of subfamily is the genus Mesembryanthemum .

Traditionally, the subfamily is divided into the following genera:

• Aptenia
• Aridaria
• Aspazoma
• Brownanthus
• Caulipsolon
• Mesembryanthemum
• Phyllobolus
• Prenia
• Psilocaulon
• Sceletium
• Synaptophyllum

In 2007 Cornelia Klak and colleagues published a phylogeny of the Mesembryanthemoideae for which they used almost all species of the subfamily. They used three molecular markers of the chloroplasts (trnL-F, rbcL-atpB, rps16) and one of the cell nucleus (ITS1) as well as 41 morphological features. The combined analysis of the chloroplast markers and the morphological features leads to the following cladogram :

Mesembryanthemoideae	Clade A   Phyllobolus Alliance  Aptenia group     Phyllobolus splendens group     Sceletium group     Aridaria group     Phyllobolus group     Prenia group     Cryophytum group  Clade B  Aspazoma group     Brownanthus group     Psilocaulon group     Mesembryanthemum eurystigmatum     Mesembryanthemum nodiflorum group  Clade C  Opophytum group     Mesembryanthemum aitonis group

Cornelia Klak and colleagues concluded from their results that it was not possible to maintain the previous genera and combined all known species in the monophyletic genus Mesembryanthemum , which contains 101 species. Sigrid Liede-Schumann and Heidrun EK Hartmann criticized the methodology of the investigations and spoke out in favor of retaining the established generic classification until a better resolved phylogeny is available.

proof

literature

• Heidrun EK Hartmann (Ed.): Illustrated Handbook of Succulent Plants: Aizoaceae AE . Springer Verlag, Berlin / Heidelberg / New York 2001, ISBN 3-540-41691-9 , pp. 13-14 .
• HD Ihlenfeldt, G. Schwantes, H. Straka: The higher taxa of the Mesembryanthemaceae . In: Taxon . Volume 11, Number 2, 1962, pp. 52-56, JSTOR: 1217212 .
• Cornelia Klak, Peter V. Bruyns, Terry AJ Hedderson: Phylogeny and New Classification for Mesembryanthemoideae (Aizoaceae) . In: Taxon . Volume 56, Number 3, 2007, pp. 737-756. - online
• Sigrid Liede-Schumann, Heidrun EK Hartmann: Mesembryanthemum — back to the roots? In: Taxon . Volume 58, Number 2, 2009, pp. 345-346. - online .

Individual evidence

1. ↑ ^{a b c d e} Heidrun EK Hartmann: Illustrated Handbook of Succulent Plants: Aizoaceae AE . 2001, p. 13
2. ^ Sigrid Liede-Schumann, Heidrun EK Hartmann: Mesembryanthemum — back to the roots? 2009, p. 345.
3. ↑ Gustav Schwantes: System der Mesembryanthemaceen . In: Succulents . Volume 1, 1947, p. 39.
4. ^ HD Ihlenfeldt, G. Schwantes, H. Straka: The higher taxa of the Mesembryanthemaceae . 1962, pp. 53-54.
5. ↑ HEK Hartmann (ed.): Illustrated Handbook of Succulent Plants: Aizoaceae . Springer, 2001, Volume 1, p. 14.
6. ↑ Cornelia Klak et al .: Phylogeny and New Classification for Mesembryanthemoideae (Aizoaceae) . 2007, pp. 741-745.
7. ↑ Cornelia Klak et al .: Phylogeny and New Classification for Mesembryanthemoideae (Aizoaceae) . 2007, pp. 750-753.
8. ^ Sigrid Liede-Schumann, Heidrun EK Hartmann: Mesembryanthemum — back to the roots? , 2009, pp. 345-346.
9. ↑ Cornelia Klak et al .: Phylogeny and New Classification for Mesembryanthemoideae (Aizoaceae) . 2007, pp. 749-750.

Web links

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