Lettowia nyassae (Oliv.) H. Rob., 2013

Robinson, Harold & Skvarla, John J., 2013, Lettowia, a new genus of Vernonieae from East Africa (Asteraceae), PhytoKeys 25, pp. 47-53 : 50-51

Lettowia nyassae (Oliv.) H. Rob. comb. nov. Figs 1 , 2A, B

Vernonia nyassae Oliver in J.D. Hooker, Icon. Pl. 14(2): 36, t. 1349B. 1881. Type: Tanzania, Higher plateau north of Lake Nyassa, Thomson s.n. (K, photo in Smith 1971: 65-67, fig. 45A-E).

Distribution.

The species occurs primarily in the area of southwestern Tanzania north of lake Nyassa, and also in eastern Zambia, Ndola, Oct 1906, C.F.E. Allen 363 (SRGH). Smith (1971) cited an outlying population of Vernonia nyassae in Transvaal (Codd & Winter 3291, K). Examination of the voucher specimen at Kew shows that it belongs to Vernonia thodei Phillips (now in Pseudopegolettia H. Rob., Skvarla & Funk, in prep.), a totally distinct entity with a different non-lophate form of pollen.

Jeffrey (1988) cited a specimen of Vernonia nyassae from the region T4, Bally 7496, from Ugalla R. (K), which is "smaller than specimens from T7 in all floral parts; it may be simply depauperate, or may indicate a populational difference."

Smith (1971) cited the following specimens as seen from within the range of the species: Tanzania: Sao Hill, 6200 feet, Feb 1959, A.M. Watermeyer 32 (K). Mbeya Distr., Slopes of Mbeya Mt., 9000 feet, 25 Sep 1936, B.D. Burtt 6331 (K). Southern Highlands Prov., Njombe Distr., Elton Plateau, 8500 feet, 6 Oct 1954, R.L. Willan 172 (K). Near Njombe, 2100 m, 17 Jan 1957, H.M. Richards 7874 (K). Zambia: Highlands, Ndola, Oct 1906, C.F.E. Allen 363 (SRGH).

Specimen examined.

Tanzania, Nyassa Hochland, Station Kyimbila, Rmubya Braubuligebirge, 1300-1500 m Seehöhe, 25 Nov 1907, A. Stolz 103 (US).

Habitat.

Evidently in savannah areas.

Figures

Figure 1. Herbarium specimen of Lettowia nyassae (Oliv.) H. Rob. & Skvarla (A. Stolz 103, US).

Figure 2. A-F SEM of pollen. A-B Lettowia nyassae (Oliv.) H. Rob. & Skvarla (A. Stolz 103, US) A View with a pore B Surface lacking pores C-F Vernoniastrum nestor (S. Moore) H. Rob. (Burundi, Prov. Burundi, Gihofi (Mosso), 20 May 1980, Reekmans 9185, US) C View with a pore D Surface lacking pores E Closer view of lacuna with a pore F Closer view of surface without pores showing extra rows of baculae.