Monographs Details: Strychnos rubiginosa A.DC.
Authority: Krukoff, Boris A. & Barneby, Rupert C. 1969. Supplementary notes on the American species of Strychnos. VIII. Mem. New York Bot. Gard. 20: 1-93, IX. 94-99.
Discussion:Type locality: Bahia (Serra de Açurua), Brazil.
Illustration: Mart. Fl. Braz. 6(1): pl. 77, fig. 1.1968.
The following are quotations from Supplement VII:
“The most important taxonomical problem in Strychnos concerns Breviflorae. In 1948 we wrote: '. . . the understanding of S. rubiginosa and its relationship to S. parvifolia, and also the true status of the poorly collected S. acuta and S. albijlora, need a thorough field investigation . .” (7a: 16). “. . . it may yet be necessary to reinstate S. fulvotomentosa as a valid species. This is amply covered in our previous papers (4: 348; 7: 10).” (7a: 70).
In 1965 we stated that “No progress on this problem was made since 1948” (7a: 16), and it is very satisfying that definite progress was made during the last, two years.
Strychnos fulvotomentosa is reinstated as a valid species and S. torresiana placed in synonymy (for details see under S. fulvotomentosa). Eight collections (some of which have been puzzling us since 1948 and which were erroneously placed with S. rubiginosa) are transferred to S. fulvotomentosa. They are from the upper part of the plants; their leaves are more heavily pubescent than those from the lower part of the plants, thus resembling in this respect S. rubiginosa.
Twelve sterile specimens from young plants (cut back vines) from Espirito Santo, and five collections from Pernambuco (largely of Ducke and Lima) are transferred from S. rubiginosa to S. parvifolia. The leaves of these collections are very different in shape and size from leaves of mature plants of S. parvifolia but they retain some of the essential features such as for example, being conspicuously verrucular (tubercles following nerves and veinlets) above and beneath.
Although substantial progress has been made in our understanding of certain species of Breviflorae from southeastern Brazil, the available collections are not sufficient for complete understanding of S. rubiginosa. Attempts are now being made to collect it in the type locality (Serra de Açurua, Bahia), and also to collect its fruits. We also plan to reexamine the type collection (Blanchet 2918). Until this is done we decided not to cite any collections, except for the type collection, and not to give its distribution.
Strychnos rubiginosa, as we understand it now, can be immediately distinguished from S. acuta and S. fulvotomentosa, especially if flowers are available. As seen from the following key its separation from S. parvifolia often presents considerable difficulties.
Anthers long13 (0.9-1.1 mm long); calyx lobes broad (broadly deltoid; leaf-blades above usually not verrucular on the nerves and veinlets or in the areoles between the veinlets; plants provided with tendrils. 58. S. acuta.
Anthers short (0.6-0.7 mm long); calyx lobes narrow (narrowly lanceolate); leaf-blades usually verrucular in the areoles between the veinlets; plants provided with tendrils; branchlets, petioles and midrib beneath with hairs greater than 1 mm long.
57. S. fulvotomentosa.
Anthers short (0.6-0.7 mm long); calyx lobes broad and short (broadly deltoid-ovate); leaf-blades conspicuously verrucular on the nerves and veinlets on both surfaces; f 55 S rubiginosa.
plants provided with spines and tendrils. “56. S. parvifolia.