Monographs Details:
Authority:
Elias, Thomas S. 1976. A monograph of the genus Hamelia (Rubiaceae). Mem. New York Bot. Gard. 26: 81-144.
Elias, Thomas S. 1976. A monograph of the genus Hamelia (Rubiaceae). Mem. New York Bot. Gard. 26: 81-144.
Family:
Rubiaceae
Rubiaceae
Description:
Species Description - Shrubs or small trees to 7 m tall; bark thin, light gray to brown; branches terete ±striate, glabrous to sparsely villous, the lenticels inconspicuous; branchlets terete to angulate, sparsely villous to densely villous, ±swollen at the nodes, the lenticels usually inconspicuous. Leaves opposite or commonly in 3's and 4's, rarely 5's; petioles glabrous to densely villous, terete, 0.8-3.4(-4) cm long; lamina ovate-elliptic, elliptic to obovate-elliptic, subacute to acuminate at apex, rounded to attenuate at base, 5.5-18 cm long, 2.6-8 cm broad, membranous to chartaceous, glabrous to densely villous above, glabrescent and finely puberulent along costa and veins to densely villous beneath, raphides usually present, lateral veins 7-10 pairs, arcuate 50° to 60°, usually conspicuous beneath, anastomosing; stipules triangular to subulate, 2.2-6 mm long, 1 mm broad at base, sparsely to densely villous, caducous. Inflorescences of modified dichasia, often helicoid and appearing cymose, terminal, borne singly or 2-4-fascicled, 16-76-flowered; peduncles terete, glabrescent to densely villous, 0.6-4.2 cm long; floral axes 1.5-4.5 cm long, ascending, often strongly so, each axis 4-9-flowered, bracts triangular, 0.6-0.8 mm long, villous, often densely so, caducous. Flowers secund, 15-25 mm long, sessile to short pediceUate, the pedicel to 1 mm long; floral tube narrowly campanulate to campanulate, 2-4 mm long, glabrescent to densely villous, raphides often present, calyx lobes ovate, 0.5-1 mm long, acute at apex, glabrescent to densely villous, persisting in fruit; coroUa tubular, orange-red to red, 12-22 mm long, tube 1.8-3 mm broad, glabrous to villous, lobes 1.3-2.5 mm long, ovate, acute at apex, erect to spreading, glabrous to villous; stamens equalling or exceeding the corolla by up to 3 mm , filaments 5.5-7 mm long, anthers 8-12 mm long, the connective forming a narrowly ovate apical appendage ca. 0.5 mm long; gynoecium 15-24 mm long, equaUing the coroUa tube, stigma 3.5-5 mm long, oblong, ±swollen, style cylindrical, ovary 5-locular. Berries cylindrical, ellipsoid to globose, 7-10 mm long, green turning red and ultimately black; the ovarian disc inconspicuous or slightly rostrate (to 1 mm long); seeds ±regular to irregular, lustrous, finely foveolate, 0.6-0.9 mm long.
Species Description - Shrubs or small trees to 7 m tall; bark thin, light gray to brown; branches terete ±striate, glabrous to sparsely villous, the lenticels inconspicuous; branchlets terete to angulate, sparsely villous to densely villous, ±swollen at the nodes, the lenticels usually inconspicuous. Leaves opposite or commonly in 3's and 4's, rarely 5's; petioles glabrous to densely villous, terete, 0.8-3.4(-4) cm long; lamina ovate-elliptic, elliptic to obovate-elliptic, subacute to acuminate at apex, rounded to attenuate at base, 5.5-18 cm long, 2.6-8 cm broad, membranous to chartaceous, glabrous to densely villous above, glabrescent and finely puberulent along costa and veins to densely villous beneath, raphides usually present, lateral veins 7-10 pairs, arcuate 50° to 60°, usually conspicuous beneath, anastomosing; stipules triangular to subulate, 2.2-6 mm long, 1 mm broad at base, sparsely to densely villous, caducous. Inflorescences of modified dichasia, often helicoid and appearing cymose, terminal, borne singly or 2-4-fascicled, 16-76-flowered; peduncles terete, glabrescent to densely villous, 0.6-4.2 cm long; floral axes 1.5-4.5 cm long, ascending, often strongly so, each axis 4-9-flowered, bracts triangular, 0.6-0.8 mm long, villous, often densely so, caducous. Flowers secund, 15-25 mm long, sessile to short pediceUate, the pedicel to 1 mm long; floral tube narrowly campanulate to campanulate, 2-4 mm long, glabrescent to densely villous, raphides often present, calyx lobes ovate, 0.5-1 mm long, acute at apex, glabrescent to densely villous, persisting in fruit; coroUa tubular, orange-red to red, 12-22 mm long, tube 1.8-3 mm broad, glabrous to villous, lobes 1.3-2.5 mm long, ovate, acute at apex, erect to spreading, glabrous to villous; stamens equalling or exceeding the corolla by up to 3 mm , filaments 5.5-7 mm long, anthers 8-12 mm long, the connective forming a narrowly ovate apical appendage ca. 0.5 mm long; gynoecium 15-24 mm long, equaUing the coroUa tube, stigma 3.5-5 mm long, oblong, ±swollen, style cylindrical, ovary 5-locular. Berries cylindrical, ellipsoid to globose, 7-10 mm long, green turning red and ultimately black; the ovarian disc inconspicuous or slightly rostrate (to 1 mm long); seeds ±regular to irregular, lustrous, finely foveolate, 0.6-0.9 mm long.
Discussion:
Type. Domingo (Dominican Republic), Jacquin s.n. P? There is apparently some confusion as to the type locality. Standley in North American Flora cites the type locality as "forest near Cartagena, Colombia." The initial description was made as a result of a voyage which concentrated in the West Indies, especially the Greater Antilles. Three years afterh. patens was first published, Jacquin (1763) published a more lengthy description of this species and cited the following: "Habitat in Domingo...." It appears that the type locality is the Dominican Repubhc rather than Colombia. A Cuban specimen labeled h. patens and collected by Jacquin was examined: Cuba, without exact locality, Jacquin s.n. (Ffra.!, ex Vienna). Leaf arrangement was extensively used as a taxonomic character by both Wernham (1911) and Standley (1934) in their work on Hamelia. Observations made on both varieties of H. patens in Panama and British Honduras and on specimens growing in the greenhouses of the Missouri Botanical Garden have shown that the number of leaves per node often depends on relative position along the stem. This may be the result of aging of the plant and the stems. The opposite condition is prevalent on the older branches, while the ternate condition is found on most of the younger branches. Four leaves per node can be found occasionally, at the junctions of small branchlets or on a single branchlet. Although five leaves per node is rare, I see no value in assigning varietal status on the basis of this character, as de Candolle did in 1830. In both varieties of Hamelia patens the mature flowers range from orange to deep red in color, with some reports of various shades of yellow. While in bud, the flowers are often yellow-orange to orange in color. As the flowers approach anthesis, all traces of yellow disappear and varying degrees of red are observed among the flowers. Upon fertilization (or poLLination?), the corolla tube becomes deep red in color, obscuring the orange, in most cases. The spread of colonies of Hamelia patens was studied in Panama. Hamelia patens is a very early pioneer in newly disturbed areas, but new seedlings do not continue to establish themselves as the stages of succession occur. Along the edges of recently (1-2 years) built unpaved roads on the island of Suskatuppu, numerous seedlings of H. patens were observed. When another roadside area (10-20 years old) was examined, no evidence of newly established Hamelia seedlings could be seen, although many bushes of considerable age were found. It appears that the requirements for germination or development of Hamelia seeds and young plants are lacking when the roadside weed flora reaches a more stable condition. Reproduction under these conditions is commonly vegetative rather than sexual. The old bushes regularly send out runners and rhizomatous branches. Development of new bushes from these structures was seen repeatedly in Panama. It is not known how common this type of vegetative reproduction is in the other species of Hamelia.
Type. Domingo (Dominican Republic), Jacquin s.n. P? There is apparently some confusion as to the type locality. Standley in North American Flora cites the type locality as "forest near Cartagena, Colombia." The initial description was made as a result of a voyage which concentrated in the West Indies, especially the Greater Antilles. Three years afterh. patens was first published, Jacquin (1763) published a more lengthy description of this species and cited the following: "Habitat in Domingo...." It appears that the type locality is the Dominican Repubhc rather than Colombia. A Cuban specimen labeled h. patens and collected by Jacquin was examined: Cuba, without exact locality, Jacquin s.n. (Ffra.!, ex Vienna). Leaf arrangement was extensively used as a taxonomic character by both Wernham (1911) and Standley (1934) in their work on Hamelia. Observations made on both varieties of H. patens in Panama and British Honduras and on specimens growing in the greenhouses of the Missouri Botanical Garden have shown that the number of leaves per node often depends on relative position along the stem. This may be the result of aging of the plant and the stems. The opposite condition is prevalent on the older branches, while the ternate condition is found on most of the younger branches. Four leaves per node can be found occasionally, at the junctions of small branchlets or on a single branchlet. Although five leaves per node is rare, I see no value in assigning varietal status on the basis of this character, as de Candolle did in 1830. In both varieties of Hamelia patens the mature flowers range from orange to deep red in color, with some reports of various shades of yellow. While in bud, the flowers are often yellow-orange to orange in color. As the flowers approach anthesis, all traces of yellow disappear and varying degrees of red are observed among the flowers. Upon fertilization (or poLLination?), the corolla tube becomes deep red in color, obscuring the orange, in most cases. The spread of colonies of Hamelia patens was studied in Panama. Hamelia patens is a very early pioneer in newly disturbed areas, but new seedlings do not continue to establish themselves as the stages of succession occur. Along the edges of recently (1-2 years) built unpaved roads on the island of Suskatuppu, numerous seedlings of H. patens were observed. When another roadside area (10-20 years old) was examined, no evidence of newly established Hamelia seedlings could be seen, although many bushes of considerable age were found. It appears that the requirements for germination or development of Hamelia seeds and young plants are lacking when the roadside weed flora reaches a more stable condition. Reproduction under these conditions is commonly vegetative rather than sexual. The old bushes regularly send out runners and rhizomatous branches. Development of new bushes from these structures was seen repeatedly in Panama. It is not known how common this type of vegetative reproduction is in the other species of Hamelia.
Distribution: