Monographs Details: Abuta panurensis Eichler
Authority: Barneby, Rupert C. & Krukoff, Boris A. 1971. Supplementary notes on American Menispermaceae. VIII. A generic survey of the American Tricilisisae and Anomospermeae. Mem. New York Bot. Gard. 22: 1-89.
Family:Menispermaceae
Scientific Name:Abuta panurensis Eichler
Description:Distribution and Ecology - BRAZIL. Amazonas: basin of Rio Negro, W . Rodrigues 1044 (INPA 7363) (INPA) (upper Rio Negro, catinga alta da Ilha das Flores), s n (INPA 1073) (INPA) (near Manaus, cachoeira do Taruma), INPA 3342 (near Manaus, Colonia dos Pintos), 3774 (near Manaus, Sao Raymundo), 20878 (near Manaus, Reserva Florestal Ducke), Krukoff 7961 and 7994 (near Manaus); basin of Rio Maues, Froes 33201 (IAN, BM), E. de Oliveira 94; basin of Rio Tonantins, Froes 12167/78; basin of Rio Iga, Ducke s n (HAMP 7708).

Discussion:

The fruit described here for the first time (Oliveira 94; Inst. Nac. Pesq. Amaz. 3774): inflorescence 2 slender, up to 7 cm long, laxly racemose ± 12-16-flowered; fruiting pedicels 6-8 mm long; drupe 18-20 mm long, 11-12 mm diam, the mealycoriaceous exocarp and very thin mesocarp together 0.4-1 mm thick, tomentulose externally, the testa of the endocarp papery or coriaceous, 0.1-0.2 mm thick.

This species, long obscure, is now known in both sexes. The typical form is characterized by leathery glabrous leaves, coarsely and prominently 3- or incipiently 5-plinerved and with subhorizontal, scalariform secondary nervation. The remarkable androecium, figured by Eichler [Fl. Bras. 13(1): PI. 42, Fig. Ill] and confirmed by comparison of an isotype (NY) with two modern collections from Manaus (Inst. Nac. Pesq. .Amaz. 3342; 20878), is a unique feature of the species. It consists of six free, plumply pear-shaped, hispidulous filaments which bear the anther-sacs laterally just below their apex, tilted forward so as to make the structurally vertical dehiscence appear oblique.

In addition to the typical form there exist in the environs of Manaus two others, still poorly understood, which we include provisionally in the species until more can be learned of their nature and relationships. The first (Inst. Nac. Pesq. .Amaz. 5586) is vegetatively similar to typical A. panurensis but has a strikingly different androecium. This is glabrous and consists of three outer free members deformed into Unear staminodia with minute sterile anthers at tip and three inner ones united halfway into a synandrium, thence greatly swollen upward and bearing the anther-sacs laterally, as in typical A. panurensis, but near the apex. The flower differs further from that of typical A. panurensis in its narrower inner sepals, densely papillate at tip both inside and out. The foliage is perhaps a trifle thinner-textured than normal in A. panurensis, and incipiently bullate. We have seen only one example of this curious plant and question whether it may not possibly represent a hybrid between A. panurensis (which might contribute the fohage and the swollen inner filaments) and some related species such as A. imene.

The second anomalous type has the staminate inflorescence and androecium of A. panurensis but differs in the foliage. The leaves of typical J. panurensis have a thick, rib-like costa elevated slightly above the surface of the blade's upper face. A flowering specimen from the Ducke Forest Reserve near Manaus (Inst. Nac. Pesq. Amaz. 20878) has, however, the leaves sulcate on the upper surface. Provisionally enlarging our concept of the species to admit this unusual plant we are able for the first time to identify as conspecific the six collections listed last above (starting with Krukoff 7961), all sterile except Oliveira 94 (already cited in description of the fruit). The barren collections were all mentioned previously [Mem. N. Y. Bot. Gard. 20(2): 8] as probably related to A. velutina but different in having dorsally glabrous, three- (not five-) nerved leaves. The mixed Ducke collection cited above consists of the same glabrous ventrally sulcate leaves associated with an Odontocarya inflorescence. This troublesome mixture is mentioned at greater length under .Anomospermum solimoesanum.

All specimens cited above were cohected on terra firme, in high forest or in catinga alta. This species apparently is very common near Manaus. It is known from the basins of Rios Negro, Maues, and Tonantins.

Distribution:Brazil South America|