I looked up A. urschianum on Tropicos. Coordinates for the collected herbarium specimens are given. I looked them up on Google Earth.
Almost all of Madagascar was once covered by dense forest. People began clearing the forest on arrival about 2,000 years ago. More than 95% of it is gone, especially west of the high spine of mountains along the eastern side of the island. In much of the island forest remains only along dense slopes above rivers, too steep for agriculture or grass to grow after burning.
East of the mountain spine prevailing wet winds are from the east, and this narrow eastern strip is wet forest. West of the spine most weather comes from the northeast during the summer. The western part of the island shades from quite wet at the north to very dry at the south. Cyclones generally come in from the east and can arrive at any time, dumping enormous amounts of rain anywhere.
The type specimen collected in 1961 has reported coordinates in what is now somebody's back yard, beside a seasonal watercourse now sustaining rice cultivation, in the surroundings of Moramanga. This is in a (now) relatively dry valley between forested north-south mountain ranges, and the Google Earth images clearly show the non-irrigated landscape as brown when they were taken. It is likely that there was once forest along this entire area, especially along the watercourse, but I don't know how much was still there in 1961.
Another specimen listed was collected in 1995 north and east of that, in what is still dense forest almost due east of Ambatondrazaka. The coordinates are not far off a track that winds generally east from Ambatondrazaka.
Last edited by estación seca; 09-12-2015 at 08:17 PM..
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