I. RANUNCULACE^. 



All the species of this natural order, which Welwitsch met with 

 in Angola properly so called — that is, between the rivers Loge 

 and Cuanza — inhabit the elevated regions in the interior of the 

 country, and they belong exclusively to the genus Clematis, com- 

 pi-ising three scandent species and one elegant erect bush. 



The Ptanunculaceje in the Flora of Huilla, including the district 

 of Bumbo, are represented by only three species of Clematis and 

 one species of Ranunculus, thus by four species altogether ; never- 

 theless they produce a striking effect upon the physiognomy of 

 the forest landscape by the presence of immense masses of two 

 erect species of Clematis, so that large tracts of pastvire ground, 

 situate amidst the forests, during the flowering season of these 

 plants, look at a distance as if covered with snow ; and this effect 

 is enhanced by the white-flowering Ce2)halaria centauroides Roem. 

 & Sch. (Welw. Herb. No. 522), which grows in company with 

 them : this happens in the months of February and March, when 

 extensive tracts of land are flooded after the rains which set in 

 about October. 



On February 8th, 1860, during an excursion towards the con- 

 fluence of the streams Lopollo and Ferao, Welwitsch enjoyed 

 ample opportunity to admire the scarcely imaginable magnificence 

 of these species of Clematis; two species, each with whitish-red 

 flowers 2 to 2 1 in. in diameter, and with stems 3 to 4 ft. high, 

 are erect, whilst a third species climbs high up the forest trees 

 and bears rather smaller white nodding flowers. 



Ranunculaceje are chiefly natives of cold or temperate zones, 

 and even in these climates they are prominent only in mountainous 

 regions of the northern hemisphere : it is therefore not surprising 

 that in Portuguese Guinea, which belongs to the equinoctial zone 

 of the southern hemisphere, this natuial order is not plentifully 

 represented, and is only seen in the interior uplands. At the 

 same time the species here found are mostly shrubby, or at least 

 woody at the base ; the Ranunculus alone forms an exception. 

 Some of the Angolan species of Clematis may be reckoned among 

 the most beautiful species of the genus, partly on account of the 

 luxuriance of their beautiful flowers and brilliant feathery tufts, 

 with which in fruit they adorn the landscape. 



Other families of plants, not specially belonging to the tropics, 



