340 



Belmontia grandis, Baker et Brown in Flor. Trop. Africa, 

 iv. 1, 553, in part. 



Exochaenium grande, Schinz in Bull. Herb. Boiss., ser. II., vi., 

 745, 802 in part. 



Tropical Africa. Nile Land: Uganda; Ankole, Doggett ! 

 Muddu, alt. 4100 ft., Brown, 139 ! Mozambique Dist. : Portuguese 

 East Africa ; Medo country, between Lajenda River and Ibo, 

 Last ! Macequeci, 2000 ft., Johnson, 260 ! Nyasaland ; Nyika 

 Plateau at Mwanemba, alt. 8000 ft., McClounie, 98 ! at Mymkowa, 

 8000 ft, McClounie, 126! Angola : Longa River, 4000 ft., 

 Baum, (» 10 ! 



This species shows close external similarity to E. grande, Griseb., 



but appears to be a distinct form. The flowers are smaller, the 



petals especially being narrower and the anthers are never fused 



together as in the short-stamened flowers of E. grande. The 



anther-glands are smaller and orbicular-ovate, and the style is 



always shorter than in the long-styled flowers of that species. 



The flowers of E. macranthum are peculiar in that, although they 



are dimorphic, they are not properly heterostyled. In all the 



flowers examined the style is of about the same length — though 



in the flowers with long stamens it is usually somewhat shorter 



than in the short-stamened flowers — but the filaments of the 



anthers may be either short, about # 5 mm. long, or long, 



about 3-3-5 mm. long. The result in these cases is that in the 



flowers with short stamens, the stamens are on a level with 



the lower part of the stigma, whilst in the flowers with long 



stamens the stamens are above the top of the stigma. This 



condition of affairs is quite different from E. grands and 



E. primulaeflorum, where the flowers are properly heterostyled, 



and long and short styles are found in correspondence with the 



long or short stamens (v. Figs. C. and D.). 



In E. macranthum the filaments of the stamens are always 

 found to be inserted at from 6-8 mm. from the base of the corolla- 

 tube in either condition of the flower, and it is the length of 

 the filaments which determines the position of the anthers. 

 The lilaments are always stout. The stout filaments and the free 

 anthers in the short-stamened flowers of this species are in 

 marked contrast to the condition of affairs in the long-stvled 

 flowers of E. grande and E. pri mulaeflorum (v. Figs. E. and F.). 

 In these two species the anthers in the long- styled flowers are 

 syngenesious and open extrorsely and the filaments are very 

 delicate (cf. Figs. 3, 4, 13 and 14). The flowers of E. macranthum 



E. grande. 



W 



A. W. Hill. 



Explanation of Plate. 



- 



A. Exorliarnium ;! mnde, short-styled flower. 



1. h lower Bhowing anthers with stout filament* and glands and the short 



style xl J. e 



2. Stamen showing glands and mode of dehiscence. 



B. E. g ninth, long-styled flower. 



3. Flower showing the syngenesious anthers and the lone stvle x 14. 



