Calenduleae

Taxobox


image_width = 225px
image_caption = "Calenduleae sp."
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
subclassis = asterids
supraordo = Campanulids
ordo = Asterales
familia = Asteraceae
Subfamilia = Asteroideae
tribus = Calenduleae
tribus_authority = Cassini
subdivision_ranks = Genera
subdivision = "Osteospermum" "Gibbaria" "Calendula" "Tripteris" "Oligocarpus" "Dimorphotheca" "Garuleum" "Chrysanthemoides"

Calenduleae is a flowering plant tribe of the family Asteraceae. Calenduleae has been widely recognized since Alexandre de Cassini in the early 1800s. [Small, J., M.Sc. (Lond.), Ph. C (1917) The Origin and the Development of the Compositae New Phytologist 16 (7): 157-177] There are eight genera and over 110 species, mostly found in South Africa. [Judd, Campbell, Kellogg, Stevens, Donoghue, ‘Plants Systematics: a Phylogenetic Approach’, Third Edition, Sinauer Associates, Sunderland, MA 2008]

It is a relatively stable clade of the Asteraceae, with minor alterations. The tribe also occurs in Southwest Asia, some Atlantic islands, other portions of Africa and Europe, with non-native occurrences in the US, Australia, and New Zealand. However, three new species within the tribe have been discovered as recently as 2003. [Nordenstam, B. (2003) Two New Species of Osteospermum (Compositae-Calenduleae)from Southwestern Cape Province, South Africa, Edinburgh Journal of Botany 60:259-265.] [Woods, A. R, Nordenstam, B (2003) An Interesting New Species of Osteospermum (Asteraceae-Calenduleae) from the Western Cape Province, South Africa, providing a Link to the Genus Chrysanthemoides 69(4):572-578.]

Description

Plants in Calenduleae vary from herbs to shrubs and usually exhibit showy flower heads. The defining characteristics separating members of this tribe from others within the family are a dimorphism of the cypselae and the fact that each cypselae lacks a pappus. ^[2] Calenduleae is named for its most economically important genus, "Calendula", known in homeopathic remedies and as a common ornamental. Other genera from Calenduleae produce ornamentals as well, including "Osteospermum" and "Dimorphotheca" (see Asteraceae for a more general description).

History and phylogeny

Cladistic arrangement of this group of plants has been recognized as far back as Andrea Cesalpino in the 1630s and again by Giulio Pontedera in the 1720s, but the official nomenclature arose after Cassini's work within the family. Early 20th-century botanists placed this tribe as sister to the Senecioneae; however, there has been molecular evidence of closer relationships between the Astereae and the Calenduleae. [Mishler, B. D, Albert, V.A, Chase, M. W, Karis, P. O., Bremer, K. R. (1996) Character-State Weighting for DNA Restriction-Site Data: Asymmetry, Ancestors and the Asteraceae, Cladistics 12 (1): 11-19] This tribe has demonstrated monophyly through chemical analysis of the similar pimerane diterpenes found within all tested species. "Osteospermum" and "Garuleum" share the highest number of identical chemical signatures, indicating close phylogenetic relationship and a more recent divergence than other genera of the tribe. [Alvarenga, S. A. V., Ferreira, M. J. P., Rodrigues, G. V. and Emerenciano, V. P. (2005) A general survey and some taxonomic implications of diterpenes in the Asteraceae, Botanical Journal of the Linnean Society 147:291-303.] One of the newly discovered "Osteospermum" has provided evidence of a link between "Osteospermum" and "Chrysanthemoides".

There have been some rearrangements of the Calenduleae tribe. "Eriachaenium" was originally lumped with the Calenduleae but has since been removed. Its placement remains uncertain, although it is now hypothesized to belong to the Cichorioideae. The genus "Castalis" has been folded into "Osteospermum". One recent analysis of the Calenduleae made several phylogenetic discoveries, including:

*the "Osteospermum" section "Blaxium" is now placed in the genus "Dimorphotheca"
*the subgenus "Tripteris" was separated from "Osteospermum"
*the genus "Oligocarpus" was separated from "Osteospermum"
*"Osteospermum sanctae-helenae", endemic to St. Helena, now belongs to "Oligocarpus". [Nordenstam, B. and Trift, I. (1999) A phylogenetic Study of the Calenduleae (Asteraceae), XVI International Botanical Congress Session 3.9.6: 3885]

Image gallery

References

External links

*cite journal
last =Nordenstam
first =Bertil
authorlink =Bertil Nordenstam
coauthors =Ida Trift
title =A PHYLOGENETIC STUDY OF THE CALENDULEAE (ASTERACEAE)
journal =XVI International Botanical Congess
date = 1999-07-07
url =http://www.biologie.uni-hamburg.de/b-online/ibc99/ibc/abstracts/listen/abstracts/3885.html
id =3885
accessdate = 2008-06-29
*cite journal
last =Cassini
first =Alexandre de
authorlink =Alexandre de Cassini
title = unknown
journal =Journal de Physique, de Chimie et d'Histoire Naturelle
volume = 88
pages =196
location =Paris
date =1794-1823
url =http://www.archive.org/details/journaldephysiqu88pari
id =J. Phys. Chim. Hist. Nat. Arts
accessdate = 2008-06-30