Genipa americana var. caruto (Humb., Bonpl. & Kunth) K.Schum.

  • Authority

    Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.

  • Family

    Rubiaceae

  • Scientific Name

    Genipa americana var. caruto (Humb., Bonpl. & Kunth) K.Schum.

  • Description

    Distribution and Ecology - Distribution. Southern Mexico (Chiapas, Oaxaca), Central America, West Indies (Cuba, St. Vincent), and South America south to Paraguay, Bolivia, and Brazil.

  • Discussion

    Genipa caruto H.B.K., Nov. Gen. & Sp. 3: 407. 1820.

    Genipa pubescens DC., Prodr. 4: 379. 1830.

    Genipa americana var caruto f grandifolia Chod. & Hassl., Bull. Herb. Boiss. II. 4: 171. 1904.

    Genipa americana var caruto f parvifolia Chod. & Hassl., Bull. Herb. Boiss. II. 4: 171. 1904.

    Type. “In ripa Orinoci et Fluminis Nigri, prope Caracas [Venezuela] et Cartha-gena [Colombia].”

    This variation of Genipa americana differs from var americana in having the lower leaf surface, including midrib and lateral nerves, pubescent. Genipa oblongifolia R. & P. approaches the var caruto in possessing pubescent midrib and lateral nerves, but the lower leaf surface is glabrous as in var americana. The interior of the calyx of var caruto is densely sericeous as in var americana, and the interior of the corolla tube shows a similar pubescence to the type found in var americana, with a zone of usually dense, hirsutulous, ascending hairs of nearly equal length to those of the basal brush, and these hairs above the basal portion continue to the basal part of the corolla lobes as elongated, conspicuous hirsute trichomes which are golden-brown in the dried state. The remainder of the upper surface of the corolla lobe interior is usually densely tomentose or papillate-tomentellose in var caruto. The stramineous cartilaginous-thickened margins in the sinuses (especially) between the calyx lobes are likewise characteristic in var caruto as in var americana. The stipules dorsally are often more pubescent, and the young tip of the branch or stem is often more strigose-pubescent than in var americana.

    This is the common variation found in Central America and southern Mexico, as well as in northern Venezuela and some other parts of South America. In the West Indies, however, it is common only in Cuba, where the type collection of G. pubescens DC. was obtained, the var americana being the common variation found in the Greater and Lesser Antilles.

    The leaf blades of var caruto are usually prominently sulcate-reticulate on the tertiary venation of the upper surface and often broadly obovate with a subobtuse base. There are pubescent-leaved collections, however, which do not show this shape or reticulate upper surface. Kuntze s n from Velasco, Bolivia, for example, has leaves densely tomentose beneath, but with an elliptic-oblanceolate shape often encountered in var americana and narrowed at both ends. The petioles of the Kuntze collection are much longer (1-1.6 cm) than is usually found in var caruto. The two forms described from Paraguay, var caruto f grandifolia and f parvifolia certainly diverge from the typical variation of var caruto, and may eventually have to be recognized as other taxa distinct from var caruto and var americana. The unusual feature of var caruto f grandifolia is the larger size of calyx and hypanthium, which in early fruiting stage measure 18-21 × 11-12 mm (calyx tube proper 5-6 mm, hypanthium 15-15 mm long), contrasted with the usual dimensions of G. americana var caruto f caruto, in which the combined length of calyx and hypanthium is only 9-13 mm. Also, the pedicels of the two flowers present on the type collection of var caruto f grandifolia are 25-30 mm long, whereas the usual lengths of the pedicels in var caruto f caruto vary from 5-13 mm. An additional notable feature present in var caruto f grandifolia is the nearly glabrate inner surface of the corolla lobes except for a small patch of short pubescence at the base, the surface bearing only sparse and minute puberulence along the upper margin and scattered pubescence elsewhere. This type of near glabrity is to be noted also in a Hassler 12403 collection from Paraguay (regione lacus Ypacaray), which has a short calyx and hypanthium similar to typical var caruto f caruto. The Hassler 3651 from Paraguay, which has a similarly large calyx and hypanthium as the Hassler 7851 collection, has the leaves glabrous below and has been placed under G. americana var americana in the present treatment. In G. americana var caruto f parvifolia the leaf blades are very narrow and comparatively much smaller than usual for G. americana var caruto (9-12 × 2.2-3.6 cm), and the corolla tube (13 mm long) is longer than in average var caruto f caruto, which varies usually from 5-8 mm long. Also, the upper surface of the corolla lobes in f parvifolia is more glabrate and in the distal half more sparsely puberulent than in ordinary var caruto f caruto, and the pubescence of the lower basal portion of the corolla lobe is shorter with less dense hirsutulous indument. Nevertheless, considering the variability of G. americana var caruto f caruto in its entirety, it would appear that the Paraguay forms represent extremes of this var caruto, which future collections may throw more light upon.

  • Distribution

    Distribution. Southern Mexico (Chiapas, Oaxaca), Central America, West Indies (Cuba, St. Vincent), and South America south to Paraguay, Bolivia, and Brazil.

    Mexico North America| Central America| West Indies| Cuba South America| Saint Vincent and the Grenadines South America| South America| Paraguay South America| Bolivia South America| Brazil South America| Honduras Central America| Guatemala Central America| El Salvador Central America| Panama Central America| Venezuela South America| Colombia South America| Ecuador South America|