Above sea-level, at the foot of the Beshtau, Mashuk and three other outliers of the Caucasus range, which protect it on the north.
The great tropical family of the Gesneraceae has left behind a few outliers: Ramondia in the Pyrenees, Haberlea in the Balkans, and Jankaea in Thessaly; the Pyrenees also possess a minute Dioscorea, sole European survivor of the yams of the tropics.
Dipterocarpeae and Nepenthaceae only extend with a few outliers into the African sub-region.
Amongst Rubiaceae, Cinchoneae with some outliers in the Old World have their headquarters at cooler levels.
The Matra group, e.g., is poorly supplied, while the outliers of the Vertes mountains towards the Danube are almost entirely wanting in streams, and have but few water sources.