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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 8, No. 3 



second stage of this succession, for example Justicia nyassctna Lindau, Leonotis 

 decadonta Gurke, and Argyrolobium shirense Taub. as tall herbs; Hewittia sub- 

 lobata (L. f.) O. Ktze., Thunbergia alata Boj., Dolichos formosus Hochst. ex A. 

 Rich., and Mikania cordata (Burm. f.) B. L. Rob. as herbaceous climbers; Ver- 

 nonia podocoma Sch. Bip., Hibiscus gossypinus Thunb., H. vitifolius L., and 

 Rubus exsuccus Steud. as erect or scrambling shrubs; Bersama abyssinica Fres., 

 Crassocephalum mannii (Hook, f.) Milne Redh., and Maesa lanceolata Forsk. as 

 small trees. Stands of Trema guineensis (Schum.) Fical. and Macaranga 17736 

 comprised the tall tree stage. 



On the steep slopes of the Rift Valley, woodlands of Brachystegia type 

 succeeded the rain forests in altitudinal zonation below the mountain-top. 

 Remnants of similar woodlands persisted as primary vegetation on the other 

 slopes, where narrow and broad strips of gallery rain forest occurred along streams. 



Collections from the area, including a few gatherings down to 2,750 feet on 

 the Nswadzi River at the southeastern foot of the mountain, totalled 241 numbers. 

 In the Nswadzi was collected the remarkable aquatic Hydrostachys 17642, at- 

 tached in masses to submerged rocks and streaming to a length of two or three 

 feet in the fast current. 



Chikwawa. This camp, our last in Nyasaland, was in the hot, malarious valley 

 of the lower Shire River. We were only 15 miles west of our Cholo Mountain 

 camp site, but over 3,500 feet below it in the bottom of the Rift and in a part 

 of the country vastly different in climate and vegetation. Before the railway be- 

 came the main route into Nyasaland in 1915, and transport was by steamboats 

 from the Zambezi, the head of navigation was about five miles below Chikwawa. 

 From Blantyre, on the Shire Highlands to the northeast, our travel distance was 

 about 30 miles by a steep, winding road with some hairpin bends on the escarp- 

 ment so sharp that the truck could not get around them without being manoeuvred 

 back and forth on the corners. For the last four or five miles the road crossed old 

 alluvial plains of the Shire, through big sprawling villages -and native cotton 

 fields on flat, fertile lands elevated above the floods. Extensive low flood- 

 plain terraces bordering the river were planted to food crops of mealies and ba- 

 nanas. The mealie crop was lush and green, and in the tassel stage of develop- 

 ment. In other parts of the country we had visited, the crop was harvested between 

 May and August. Two crops of mealies could be produced here in the year. The 

 people of the lower Shire had a priceless asset in their moist alluvial flats. 



Through official courtesy we had as headquarters the district commissioner's 

 residence at Chikwawa government station, vacant owing to shortage of personnel 

 in the ppstwar period. This, and the territory we wished to work in, were on the 

 west side of the Shire. The fast, eddying river, about 150 yards wide, was 

 crossed on a steel pontoon manned by native ferrymen. Under control of a boss, 

 one man steered and fended with a long bamboo pole, and nine paddlers in a boat, 

 on the end of a long warping rope, raced to the other bank and made fast before 

 the pontoon, already cast off into the current, drifted too far towards rapids which 

 broke the river around an island downstream. The operation had elements of risk, 

 but it was beautifully timed. 



The official residence overlooked the river from a steep bluff about half a mile 

 above the ferry. The high bank rose directly from the water to a height of about 

 80 feet and appeared to be the eroded edge of an ancient floodplain which ex- 

 tended back from the river for two or three miles. Elevation above sea level was 

 about 350 feet. 2 Smoke haze from grass-fires, which burned day and night on the 



2 On aneroid readings, subsequently found incorrect, an altitude of 200 m. (approxi- 

 mately 650 ft.) was given on the botanical field labels. 



