Bonamia douglasii
Nomenclature
Accepted name/Authority/Place of publication:
Bonamia douglasii D. F. Austin, sp. nov. Novon, Vol. 4, No. 4 (Winter, 1994), pp. 319-321
TYPE:Nicaragua. Dept. Chontales: Hacienda Veracruz,12011'N, 85?22'W, elev. 120-140 m,pastures and gallery forest, 19 Dec. 1984 (fls& buds), W. Douglas Stevens 23522 (holotype,MO; isotype, FAU). Figure 1
Description
Habit:
Perennial climbers, woody, the stems twining, appressed brown-sericeous when young, glabrescent, older stems brown, lenticellate, striate.
Leaves:
Leaves simple, petiolate; lamina coriaceous, elliptic to broadly ovate, 2.5-5.8 cm long, 1.8-5 cm wide, entire, the apex obtuse to mucronate, apiculate, the base obtuse to rounded, brown-sericeous, 4-6 veins conspicuous below, obscure above; petiole canaliculate, 2-5 mmlong, 2 mm wide, brown-sericeous.
Inflorescences:
Inflorescences racemose to flowers solitary, near the ends of terminalor on lateral branches, peduncles reduced toca. 2 mm on solitary flowers, 3-4 mm long in racemes, brown-sericeous; pedicels 5-8 mm long, brown-sericeous; bracts scalelike, 1.5 mm long, triangular, brown-sericeous;
Flowers:
Sepals unequal, imbricate, the outer longer and broader than the inner, reniform, 8-9 mm long, 9-12 mm wide, coriaceous, basally obtuse, apically rounded, the margins entire, undulate, brown-sericeous, the inner 6-7 mm long, 3-5 mm wide, chartaceous, glabrous; corolla induplicate-valvate and convolute, funnel-shaped, 16-18 mm long, white, brown-sericeous on the midpetaline bands with V-shaped trichomes, the cylindrical tube 6-7 mm long, glabrous; the limb almostentire; stamens equal, included, 4-5 mm long, the filaments fused to the corolla tube, glabrous at the base, the anthers 1-1.5 mm long; nectary 5-lobed; ovary ovoid, 2.5 mm wide and long, brown-sericeous throughout most of the length, the trichomes V-shaped, some areas near the bottom glabrous, thestyles 2, unequal, 5-7 mm long, the stigmas capitate,1 mm wide.
Fruits:
Fruits not seen.
References:
Novon, Vol. 4, No. 4 (Winter, 1994), pp. 319-321
Other information
Authorship for webpage
Editor:
Esmond Er
Contributors:
In Central America this species superficially resembles Bonamia sulphurea (Brandegee) Myint & Ward, which is now known from Guatemala, Honduras, Mexico (Veracruz) (Myint & Ward, 1968), Panama (Austin, 1975), and Colombia (Santander,Uribe 3950, US). If the Stevens specimen had been collected in South America it might have been confused with B. ferruginea (Choisy) Hallier f. Thislatter species shares with the Mesoamerican plants the short pedicels. The two may be distinguished by the capitate inflorescences with 10 or more flowersin B. ferruginea, and racemose inflorescences with fewer than 10 flowers in B. douglasii.
The fact that the outer sepals are larger than theinner in B. douglasii makes it unique among theCentral American and North American species of Bonamia. The trait, however, does occur in otherspecies of the genus, including: B. cordata (Hallierf.) Hallier f., endemic to the Malagasy Republic; B.ferruginea (Choisy) Hallier f., from the upper Amazonin South America; B. kuhlmannii Hoehne,known from only the type collection in Matto Grosso, Brazil; B. mossambicensis (Klotzsch) Hallier f., known from Mozambique and Tanzania; B. pannosa R. Brown, endemic to central and western Australia; and B. peruviana v. Ooststroom, found only near Departamento Loreto in Peru. Thus, the large outer sepals in Bonamia have arisen in four areas: Central America, South America, Africa-Madagascar, and Australa.
Moreover, having outer sepals larger than theinner or outer sepals enlarging in fruits has arisen several times within the family, including in oneform or another Aniseia Choisy (Merremieae D. F.Austin), Bonamia A. Thouars (Cresseae Bentham & Hooker), the entire tribe Poraneae Hallier f. with nine genera, Hildebrandtia Vatke (Hildebrandtieae Peter), and Jacquemontia Choisy (Convolvuleae(Choisy) Choisy). Surely there must be some strong force(s) selecting the trait in this suite of species within Bonamia and across the family. In some situations the large sepals appear to function as wings for wind-dispersal or maybe water-dispersal. In other cases the larger outer sepals may functionto prevent insects biting through the calyx to robthe flower of nectar. No studies of the function(s) have been made.