Euphorbia fianarantsoae Photo by: © Plantemania
Origin and Habitat: Euphorbia fianarantsoaeSN|35319]]SN|35319]] is Endemic to the High-Plateau near Fianarantsoa, Madagascar. It is likely to have a small extent of occurrence and area of occupancy, which has yet to be ascertained.
Altitude range: Around 1200-1600 metres above sea level.
Habitat and Ecology: This species grows in sub-humid areas on rocky outcrops and inselbergs, where it forms dense thickets together with Pachypodiums densiflorum and other succulents. It is endangered by human activities (habitat degradation, fire, collection for horticulture.)
Synonyms:
Description: Euphorbia fianarantsoae is a spiny, succulent shrub up to 50 cm tall, branching densely from the base. The leaves are lanceolate, clustered at the tip of the branches. The inflorescence is a cyathium with yellow or or reddish yellow bracts that form a cup-shaped petal-like structure around a female flower surrounded by five male flowers. The inflorescences appear at the top of the stems and are typically like the flowers exhibited by the Euphorbia millii complex.
Derivation of specific name. Fianarantsoae For the occurrence near Fianarantsoa, Madagascar.
Branches. Simple, about 15 mm in diameter.
Leaves: Clustered at branches tips, to 30 mm long and 11 mm wide, succulent, green with red margins, becoming bright red.
Stipular spines. 5-15 mm long not thickened at the base, in 8 irregular series.
Inflorescences (cymes): 1- to 2-forked with 2 to 4 cyathia. Peduncles 5 mm long. Cyathophylls spreading, rounded, to 11 mm long and 7 mm wide, yellow turning red.
Flowers (cyathia): 5 mm in diameter; nectar-glands ovate, yellow. Ovary sessile
Taxonomy: The taxonomic status of this species is problematic and possibly just a variety of Euphorbia milli. E. fianarantsoae is similar to Euphorbia delphinensis, Euphorbia ankazobensis and Euphorbia duranii.
Bibliography: Major references and further lectures
1) Urs Eggli "Illustrated Handbook of Succulent Plants: Dicotyledons" Volume 2. Springer, 2002Werner Rauh, “The Wonderful World of Succulents: Cultivation and
2) Description of Selected Succulent Plants Other Than Cacti”, Smithsonian Institution Press, 1984
3) Rauh, W. “Succulent and Xerophytic plants of Madagascar”. Vol I. Strawberry Press, Mill Valley. 1995
4) Rauh, W. “Succulent and Xerophytic plants of Madagascar”. Vol II. Strawberry Press, Mill Valley. 1998
5) Walter Röösli, “Pachypodiums in Madagascar”. books on Demand, 29 September 2017
6) Haevermans, T. 2004. Euphorbia fianarantsoae. The IUCN Red List of Threatened Species 2004: e.T44349A10894698. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T44349A10894698.en. Downloaded on 19 August 2018.
7) Urs Eggli, Leonard E. Newton, “Etymological Dictionary of Succulent Plant Names”, Springer Science & Business Media, 29 June 2013
8) Ursch, E. & J. Leandri. “Les euphorbes malgaches epineuses et charnues du Jardin Botanique de Tsimbazaza”. Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 5: 109–185. 1954
9) Euphorbia fianarantsoae, in World Checklist of Selected Plant Families, Board of Trustees of the Royal Botanic Gardens, Kew. URL https://wcsp.science.kew.org/namedetail.do?name_id=79663
10) Schill, R. “Cytotaxonomische untersuchungen an sukkulenten vertretern der gattung Euphorbia L. aus Madagaskar.” Ber. Deutsch. Bot. Ges. 84(1/2): 71–78. 1971.
11) Buddensiek, V. “Sukkulente Euphorbien.” 1–176, 1998.
12) "Euphorbia fianarantsoae." Wikipedia, L'enciclopedia libera. 26 mar 2018, 16:31 UTC. 19 ago 2018, 16:45 <//it.wikipedia.org/w/index.php?title=Euphorbia_fianarantsoae&oldid=95716405>
