Strychnos brachiata Ruiz & Pav.

  • 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.

  • Family

    Loganiaceae

  • Scientific Name

    Strychnos brachiata Ruiz & Pav.

  • Description

    Species Description - Mature fruits globose, very large (only fruits of S. tomentosa and S. ramentifera approach their size), up to 14 cm in diam; shell thin, about 2 mm thick, hard but fragile, shining, smooth, testa crustaceous; seeds many, more or less discoid, about 26 mm in diam; fruit-pedicels about 10 mm in diam; pulp is edible, of pleasant odor and taste (Black 48-2948 and others). Fruits and seeds resemble those of S. eugeniaejolia.

  • Discussion

    10. Strychnos brachiata Ruiz & Pavon, Fl. Per. 2: 30. 1799. Strychnos blackii Ducke, Bol. Técn. Inst. Agron. Norte 19: 22. 1950. When we were working on the monograph, flowers of this species were known to us only from the old type collections deposited with Field Museum of Natural History, Chicago. Several other sterile collections were placed under S. brachiata and cited in our subsequent papers (5, 6)4 (7a). In connection with the preparation of Supplement VII, we reviewed S. blackii, which was described by Ducke in 1950, and stated: “. . . in the flower characters this species is very close to S. brachiata. However, flowers of S. brachiata were described by us in the monograph only from the very old collections of Ruiz and Pavon and new collections may yet permit us to separate it from S. Blackii on some characters of diagnostic value.” Now a type collection of S. brachiata with excellently preserved flowers has become available. The young leaves of this collection match very well those of the type collection of S. blackii. In fact, they are so alike that they could have come from a single branchlet. Inflorescences and flowers of the two type collections are alike in all essential details. Externally the corolla-tube in both collections is fulvous-pilosulous, the longer hairs giving out at the middle of the lobes and the lobes themselves being papillose on both sides. Internally the tube is glabrous for a space of ±2 mm measured from the base, thereafter pilosulous upward. There is no essential difference in the pedicels; the length depends on whether one chooses the flower central to the cymule or lateral to it. In the type collections of S. brachiata and S. blackii the following differences were observed: S. brachiata: calyx-divisions 2-2.5 mm long, corolla-lobes ±3 mm long; anthers oblong, 1.4 x 0.65 mm long, sessiloid (filament 0.05 mm). S. blackii: calyx-divisions 1-1.4 mm long; corolla-lobes ±2 mm long; anthers oblong-obovate, 0.9-0.95 x 0.5 mm long; the filament and attachment as in S. brachiata. In a second flowering collection of S. blackii (Black 1+8-291+8) we find the corolla-lobes reach a length of 2.6 mm, scarcely shorter than in the type of S. brachiata, and we question the significance of the slightly shorter anthers and calyx-lobes in this one population. Fruits of S. blackii up to 14 cm in diam, shell fragile, ±2 mm thick, seeds many, whereas Ruiz and Pavon describe the fruits of S. brachiata as about 7.5 cm in diam, shell fragile and seeds 4. Except for the number of seeds, which is often very variable in some of the species of Longiflorae, there are, therefore, no significant differences in fruit characters. Under the circumstances, there is no ground for retaining S. blackii as a valid species. S. brachiata, as it is now understood, has a very extensive range extending from sub-Andean Peru eastward to Furos de Breves in the State of Para, Brazil. A large bush-rope found in various habitats including varzea and terra firme. In Supplement VII (see 7a: 26, 27), Froes 31935 through typographical error is cited as "Froes 31953." Prance & Silva 59203, placed with this species with doubts, matches well Froes 21765 and Pires 3695 (see 7a:26). This probably is an undescribed species but it is best to cite specimens here until flowers (and/or fruits) are collected and it is better understood. At that time it will be necessary to re-examine again 4 sterile specimens from sub-Andean Bolivia and Venezuela. Prance & Silva 59203 is a voucher for a sample of root bark sent to Prof. Marini-Bettolo for chemical studies.