Dracaena braunii Engl.

Damen, T. H. J., Burg, W. J. van der, Wiland-Szymańska, J. & Sosef, M. S. M., 2018, Taxonomic novelties in African Dracaena (Dracaenaceae), Blumea 63 (1), pp. 31-53 : 33-35

4. Dracaena braunii Engl. — Map 4

Dracaena braunii Engl. (1892) 479. — Lectotype (designated here): culta Berlin s.n. (lecto B [B_10_0184054]) (ex. Cameroon, Malimba, 1889, Braun 329), Aug. 1891.

Dracaena litoralis Mwachala & Eb.Fisch.(2013) 444. — Type: Mezili 90 (holo P [ P00283988 , P00283989 ]), Cameroon, Kribi District , between Kribi and Lonji, 19 Mar. 1968, syn. nov.

Distribution — Cameroon, Equatorial Guinea, Gabon, Re- public of the Congo.

Notes — Dracaena litoralis was recently described to accommodate a plant similar to the original material of D. braunii (type and plate in protologue of cultivated plant) but with smaller flowers and different leaf shape. However, we think the differ- ence in the flower size is explained because D. braunii was based on cultivated material in which the flower size is often a little larger (phenotypic plasticity due to better growing condi- tions?). For example, a flower measured in Gabon (Damen et al. 499) was 18 mm long, but when this plant was transplanted and flowered in the greenhouse at WAG, the flower was 22 mm long. Flowers in D. braunii are nocturnal and only a few hours at full anthesis (Damen, pers. obs.). In the field, collections are usually made when the flowers are not yet at full anthesis and therefore still slightly smaller. In cultivation, where often the light levels are lower, full anthesis starts earlier during the evening and it is easier to collect the flowers at full anthesis. These phenomena could thus well explain the difference in flower size observed by Mwachala & Fischer (2013). Moreover, we have been able to study D. braunii populations in the field, which occurred to be very polymorphic, possibly due to the extreme growing conditions, (salty places near the coast often grazed by buffalos). From those observations we conclude that leaf shape and phyllotaxis of D. litoralis fit comfortably within the range of D. braunii , as does the characteristic ecology.

In his unpublished PhD thesis, Mwachala (2005) selected Plate 20 in the protologue ( Engler 1892: 479) as a lectotype for D. braunii . In that protologue, however, Engler cited a culti- vated plant: “Die Pflanze wurde von J. Braun nach dem botan. Garten zu Berlin importiert und blühte daselbst im Aug. 1891.” According to the label attached to the herbarium sheet in B with barcode B_10_0184054, it represents material from that plant and should thus be regarded as the original material to be preferred over a plate. This corrected typification was already communicated by Mwachala & Fischer (2013).