Monographs Details: Strychnos blackii Ducke
Authority: Krukoff, Boris A. 1965. Supplementary notes on the American species of Strychnos VII. Mem. New York Bot. Gard. 12: 1-94.
Description:Distribution and Ecology - Brazil: Para: basin of Rio Amazonas (Furos de Breves, Rio Tajapurú, Igarapé Pixuna, perto do lugar Antonio Lemos), Black 48-2935 (July 17, 1948) (type coll.) 48-2948 (July 19, 1948); Ducke s.n. (H. J. B. R. 22364) (Sept. 25, 1926), Froes 31953 (June 3, 1953) (cabeceira do Rio Uruará, munic. Prainha, flanco do planalto, terra-firme).
Discussion:I have not seen Froes’ and Black’s collections of this species from the Territory of Amapa (Rio Macacoari, near Macapá) ; Froes’ collection from the State of Amazonas (mouth of Rio Solimoes, near Manaos, Fazenda Santo Antonio) and Froes’ collection from a plateau between the rivers Xingu and Tapajos to which Ducke refers in his papers (31: 28; 33: 78).
The first collection of this species (leaves and old inflorescences) made by Ducke on Sep. 25, 1926 was sent to us for identification and I wrote to Ducke on Jan. 22, 1947 that it was probably of a new species, related to S. brachiata, which however we do not like to describe in the absence of flowers. This specimen (Ducke, s.n.; H.J.B.R. 22364) is deposited at The New York Botanical Garden with our annotation label reading: “Strychnos sp. nov. (?) aff. S. brachiata Ruiz and Pav. One frag, flower seen too poor for conclusive decision.” In July 1948 at Ducke’s request, Black was sent to the place where the above referred to specimen was collected (Ducke’s letter to me of Oct. 3, 1948) and he obtained a flowering specimen, (Black 48-2935). Ducke described this as a new species.
A huge bush-rope provided with tendrils which abounds on varzea and on terra-firme.
In the flower characters this species is very close to S. brachiata. However, flowers of S. brachiata were described by us in the monograph on the very old collections of Ruiz & Pavon and new collections may yet permit us to separate it from (S. Blackii on some characters of diagnostic value. As per Ruiz & Pavon, fruits of S. brachiata are ±7.5 cm in diam. and with a few seeds (about 4) (1: 269), whereas, as per Ducke, a single perfect fruit of S. Blackii seen by him is 14.0 cm in diam. and with many seeds (31) (l.c.). The former species is known from sub-Andean Venezuela, Colombia, Peru and Bolivia, whereas the latter, from Amazonian Brazil. In the systematic arrangement of the species, I am placing it next to S. brachiata where it obviously belongs.
Its fruits are known and were described by Ducke (31: 21, 55). In his key made on the basis of fruit characters, it comes together with eight other species of Longiflorae (S. eugeniaejolia, S. trinervis, S. divaricans, S. toxifera, and S. tomentosa, also S. brachiata, S. panamensis and S. tabascana).
It would be important to collect a series of specimens from various parts of mature and young plants so that we could distinguish it on the basis of sterile material with more confidence.
Distribution:Brazil South America