1954] 



PLANTS COLLECTED IN NYASALAND 



41 



the calyx, and more distantly toothed leaves. From P. pubescens Bak. it differs 

 in the smaller bracts and shorter teeth of the fruiting-calyx. 



Plectranthus elegans Britten, Trans. Linn. Soc. II. Bot. 4: 36. 1894; Bak. in 

 Thiselton-Dyer, Fl. Trop. Afr. 5: 411. 1900. 

 Coleus mahonii Bak. in Thiselton-Dyer, Fl. Trop. Afr. 5: 434. 1900. 

 Plectranthus mahonii (Bak.) N. E. Br. ex Hook. f. Bot. Mag. pi. 7818, 1902. 



Mlanje District: Mlanje Mountain; Luchenya Plateau, common on forest-edges, 

 herb 1-2 m. high, aromatic, branches numerous, erect, flowers deep purple, fruit- 

 ing calyx purple, later brown, 1890 m., June 30, 1946, 16542, Endemic to 

 Nyasaland. 



I cannot distinguish P. mahonii, based on a cultivated plant, from P. elegans, 

 Purves 80 (Tuchila Plateau, Nyasaland, 1800 m., Aug. 1901) in Herb. Kew. is 

 also P. elegans, 



Plectranthus swynnertonii S. Moore, Jour. Linn. Soc. Bot. 40: 176. 1911. 



Mlanje District: Mlanje Mountain; Luchenya Plateau, a common constituent 

 of primary forest undergrowth, shrub 2-3 m. high, flowers very pale purple, 1890 

 m., July 12, 1946, 16810, New to Nyasaland; previously known only from S. 

 Rhodesia. 



Our plant has rather larger flowers than the S. Rhodesian specimens. P. 

 swynnertonii differs from P. elegans Britten in its more irregularly cut leaves, 

 and in having bracts fringed at their apex with rather long pericellular hairs with 

 violet cross-walls. 



Plectranthus swynnertonii S. Moore var. ? 



Mlanje District: Mlanje Mountain; Luchenya Plateau, common epiphyte on 

 trunks of leaning trees in forest, herb 40-60 cm. high, ascending or erect, inter- 

 nodes swollen, flowers white, 1890 m., June 30, 1946, 16536; ibid., locally com- 

 mon in forest undergrowth, herb about 50 cm. high, internodes swollen, flowers 

 white, 1890 m., July 6, 1946, 16695. 



The leaves of these two numbers are more attenuate at base than in P. 

 swynnertonii, where they are truncate or subcordate; and the flowers are all ap- 

 parently cleistogamous. Otherwise there is not much between them. More material 

 is wanted to test the constancy of the cleistogamy, and also more of P. 

 swynnertonii from S. Rhodesia. 



In their leaves Brass 16536 and 16695 look intermediate between P. swyn- 

 nertonii and P. elegans Britten, and I cannot help suspecting the possibility of 

 their being hybrids. Both the possible parents were also collected by Mr. Brass 

 on the Luchenya Plateau, but unfortunately he does not say whether they were 

 growing together or not, or how the possible intermediates occurred. 



Plectranthus laxiflorus Benth. in E. Mey. Comm. PI. Afr. Austr. 228. 1837; in 

 DC. Prodr. 12: 63. 1848; Cooke in Thiselton-Dyer, Fl. Cap. 5 1 : 276. 1910. 

 Plectranthus violaceus Gurke, Bot. Jahrb. 19: 201. 1894; Bak. in Thiselton-Dyer, Fl. 



Trop. Afr. 5: 413. 1900. 

 Plectranthus kondowensis Bak. in Thiselton-Dyer, Fl. Trop. Afr. 5: 417. 1900. 



North Nyasa District: Nyika Plateau, occasional in shrubby borders of mon- 

 tane forest, herb 2 m. high, leaves purple beneath, flowers white, middle lobe of 

 upper lip pale purple, 2250 m., Aug. 16, 1946, 11256, Uganda, southwards to 

 the Cape. 



I consider that P. kondowensis and P. violaceus are not separable specifi- 

 cally from the South African P. laxiflorus. 



