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FLORA OF MADAGASCAR. 255 
“is a close ally of the nearly extinct blackwood and redwood of 
St. Helena." Zhodoclada is a doubtful member of the Order 
Linacem. Trimorphopetalum is an insignificant monotypic herb, 
nearly allied to Zmpatiens, inhabiting the streams in the forest on 
the eastern confines of Imerina.  Colvillea is a plant possessing a 
long raceme of large handsome red flowers and somewhat sensitive 
leaflets. The two species of Neobaronia, noticed later on, are 
amongst the most remarkable trees in the whole island. The 
Dichetanthera are forest trees, which are very beautiful when in 
full bloom. Schismatoclada, of which four species have been 
described, are shrubs or trees closely allied to Cinchona. The 
bark may possibly be worth analysis. Pycnoneurum, of which there 
is but one species, is an insignificant herb growing in the open 
country. The species of Zachiadenus are herbs with white or 
blue, crateriform, very long-tubed, corollas. T. longiflorus is said 
to possess purgative properties. .Dilobeia is a large tree with 
leaves doubly bifid when young, and singly bifid when mature. It 
possesses dicecious inconspicuous flowers and a hard indehiscent 
oblong fruit about 1} in. long. 
I have long been convinced that the flora of Madagascar may 
be divided into three Regions, and the data given below will, I 
think, justify the conviction. These Regions run ina longitudinal 
direction, following approximately the longer axis of the island. 
I propose to call them Eastern, Central, and Western. The 
Central Region includes the elevated plateau of the interior, 
that is to say, the territory bounded on the east by the western 
edge of the great forest, on the west by the high land, from which 
there is generally a more or less distinct descent into the western 
lowlands, on the north by Lat. 14°, and on the south by the tropic 
of Capricorn. Its limits may be more definitely traced thus :— 
From the tropic of Capricorn and Long. 46° 50' the line runs 
about 15 miles east of Ihosy, thence to Ikalamavony, passes a few 
miles to the east of Ankavandra, turns north-east to Malatsy and 
Antongodrahoja, on to Isomboana, follows the range of mountains 
in the province of Befandriana, then up to a point halfway 
across the island in Lat. 14°; coming south, it skirts the great 
forest until it reaches the mountain of Ambiniviny, it then takes 
a direction a little west of south until it again reaches the forest 
to the west of Ambatondrazaka (thus shutting out the great 
Antsihanaka province), which it skirts until it meets the tropic 
of Capricorn. By connecting the northern point with Port 
Lonky (or Loquez), and the southern point with the mouth of 
