Acalypha rubrinervis
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Acalypha rubrinervis is an extinct species of the milkweed family. It was endemic to St. Helena .
Systematics
Acalypha rubrinervis was first described by William Roxburgh as Acalypha rubra in 1816 . However, this name is pre-occupied and therefore invalid. It is a younger homonym because Acalypha rubra was used as a synonymous name for Acalypha phleoides by Carl Ludwig Willdenow as early as 1809 .
description
Acalypha rubrinervis was a shrub or small tree that reached a height of one to two meters. The branches were covered with bumpy scarring. The leaves were ovate to broadly triangular-ovate, with entire margins to slightly notched with three veins at the base of the leaf blade. The leaf blade was 5 to 7 inches long and 3 to 5 inches wide. The 2 to 6 centimeters long petioles and the leaf veins were red. The graceful hanging, thread-like male inflorescence consisted of 20 centimeters long red spikes, to which the species owes its common English name " stringwood ". The female flowers had two centimeters large hemispherical, cap-shaped light red bracts and a sessile bare three-chambered ovary. There were three scars that were a little feathered. The male flowers were 0.5 to 1 mm long and sat like grapes in the axils of the lanceolate bracts. The flowering period was in April and May.
Occurrence
Acalypha rubrinervis was endemic in the central mountains of St. Helena and occurred at altitudes above 600 m. Locations were the region of Round Tower and the south side of Diana's Peak dominated by thickets .
die out
Acalypha rubrinervis was already considered very rare when it was discovered in 1806. One possible cause of the species' disappearance was goats, which destroyed the vegetation. In 1843 Joseph Dalton Hooker noticed that Acalypha rubrinervis was extinct. In 1855, however , John Charles Melliss discovered yet another example, which was received in 1870.
literature
- QCB Cronk: The endemic Flora of St Helena. Anthony Nelson Ltd, Oswestry, 2000, ISBN 0-904614-35-2 .
- William Botting Hemsley, C. Wyville Thomson, John Murray: Report on the scientific results of the voyage of HMS Challenger during the years 1873-76: under the command of Captain George S. Nares, RN, FRS and Captain Frank Turle Thomson, RN (1885) (described as Acalypha rubra)
Web links
- Acalypha rubrinervis in the endangered Red List species the IUCN 2008. Posted by: QCB Cronk, 1998. Retrieved on 10 November, 2008.