Drosera katangensis Taton

Rjosk, A., Neinhuis, C., Monizi, M. & Lautenschläger, T., 2022, Synopsis of the genus Drosera (Droseraceae) in Angola and the Democratic Republic of the Congo, Blumea - Biodiversity, Evolution and Biogeography of Plants 67 (1), pp. 1-14 : 10

7. Drosera katangensis Taton — Fig. 9

Drosera katangensis Taton (1945c) 309;G.C.C. Gilbert (1951) 550,A.S.Rob. et al. (2017) 1422. —

Type: H. Homblé 773 (holo BR), DRC, Lualaba . Plateau de la Manika , Nov. 1912.

Caulescent herb. Stems up to 15 cm long, erect, densely glandular ( Fig. 9b ). Leaves alternate, sparsely dispersed, basal leaves smaller; stipules c. 2 mm long, apex lacerated into setaelike segments; lamina oblong-spathulate, 5–15 by 1.5–5 mm, abaxially pilose ( Fig. 9a ); petiole 7–20 mm long, densely pilose/ hirsute. Inflorescences cymose, with up to 8 flowers; peduncles 1, up to 20 cm long, erect at the base, densely pilose/hirsute (often recurved hairs); bracts linear to lanceolate, c. 5 mm long, glandular; pedicels 2–3 mm long, pilose. Sepals 5, oblong, c. 8 by 2 mm, apex obtuse, adaxially densely pilose/hirsute. Petals 5, obovate, c. 12 by 4 mm, pink or pinkish. Stamens 5; filaments c. 6 mm long; anthers c. 1.5 mm long, sagittate. Pistil: ovary ovoid; styles 3, bipartite to the base, branches 2.5–3 mm long, ascending. Seeds fusiform, black.

Distribution — DRC ( Fig. 9c ).

Habitat & Ecology — Wet plains.

Additional specimens (see Fig. 9d for province map). DRC, Haut- Katanga, 63 km au N du Poste de Katshupa, Plateau des Kundelungu , alt. 1685 m, 28 Jan. 1967, F. Malaisse 4986 ( BR) ; Lusinga, Plateau des Kibara , 14 Apr. 1969, S. Lisowski et al. 4659 ( BR) .

Note — So far, this species has been collected only from Katanga Province ( DRC), but it is likely to occur in neighbour- ing regions. The herbarium specimens (F. Malaisse 4986 and S. Lisowski et al. 4659) share characters with D. flexicaulis and D. elongata (elongated stem, erect leaves) as well as with D. bequaertii (erect base of the peduncle, hairiness of leaves and peduncle). Since only few specimens have been collected so far, this species is not well studied. The shared characters with D. flexicaulis , D. elongata and D. bequaertii indicate that D. katangensis could be a hybrid of the above mentioned species ( Robinson et al. 2017). The specimen Homblé 774 in particular could support that thesis. While three of the four plants are easily identified as D. flexicaulis , one plant looks similar to D. katangensis showing the erect base of the inflorescence and similar leaf shape and arrangement but it has only sparsely pilose petioles and stem. The examination of fresh material and molecular genetic analysis might shed further light on the taxonomic status of D. katangensis .

Figures

Fig. 9 Drosera katangensis Taton. a. Leaf shape with pilose petiole and oblong-spathulate lamina; b. general morphology: caulescent, sparsely dispersed leaves and laterally arising, erect inflorescences; c. distribution according to the literature; d. province map of Angola and DRC with localities of examined herbarium specimens. — Scale bars: a = 1 cm; b = 2 cm.