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Published In: Histoire des Plantes de la Guiane Françoise 1: 314, t. 122. 1775. (Jun-Dec 1775) (Hist. Pl. Guiane) Name publication detailView in BotanicusView in Biodiversity Heritage Library
 

Project Name Data (Last Modified On 2/15/2012)
Acceptance : Accepted
Project Data     (Last Modified On 3/9/2012)
Notes:

Coutarea is characterized by its woody habit; lack of raphide crystals in the tissues; opposite leaves; interpetiolar, triangular, generally persistent stipules; terminal, bracteate, cymose, generally few-flowered inflorescences; bisexual, homostylous, generally rather large flowers with 5 to 7 calyx lobes, corolla lobes, and stamens; tubular to broadly funnelform, actinomorphic to weakly zygomorphic corollas with the lobes imbricated in bud; stamens inserted near the base of the corolla and often arranged all together on one side of the flower, by twisting of the long filaments; cylindrical stigmas borne on long styles; ovary with 2 locules and numerous ovules in each locule on axile placentas; woody capsules that are generally elliptic to orbicular in outline, strongly flattened perpendicular to the septum, and septicidal from the apex; and numerous flattened, generally orbicular seeds with a concentric marginal wing. The corollas are generally showy and variously white to pink or red. Because the flowers sometimes have a slightly zygomorphic corolla and 6 lobes and the anthers arranged all on one side, Coutarea is sometimes not recognized as a species of Rubiaceae. The capsules that are flattened perpendicular to the septum are distinctive. This genus characteristically is found in rather dry seasonal vegetation, except for C. hexandra, which is widespread ecologically as well as geographically. Plants from drier habitats often have a weakly to well developed "short-shoot" or brachyblast growth form, with the well developed internodes on the main stem and the leaves and flowers mostly borne on lateral stems with reduced internodes. Coutarea belongs to a group of genera whose relationships are poorly understood; in recent studies this group has been called the "Catesbeeae-Chiococceeae-Exostema Complex (Robbrecht & Manen 2006, p. 116).

Coutarea is very similar to Exostema, and these can be confused. Exostema in general can be separated by its capsules that are not flattened, its corollas that are salverform with a generally very narrow cylindrical tube, and its stamens that are positioned symmetrically and exserted on very well developed filaments; in contrast, Coutarea has the flattened capsules, corollas that are tubular to funnelform with the tube moderately to very broad; and the stamens often arranged all one side of the flower, with the anthers included to shortly exserted. However there are two species classified provisionally in Exostema from the Andes of South America, E. corymbosum and E. maynense, that have flattened capsules similar to those of Coutarea but flowers similar to those of Exostema. These species are considered somewhat doubtful in terms of their relationship to the other species of Exostema, but do not fit morphologically in Coutarea either. Exostema corymbosum is a shrub found in Andean valleys of Peru, and has been confused with Coutarea andrei; Exostema maynense is a large tree of lowland rainforests of the western Amazon basin. Also similar are Coutaportla and Hintonia of Mexico and Central America. Coutaportla can be separated from Coutarea but its fewer seeds, 2-5 per locule, on basal placentas and its flowers with 4-5 calyx lobes, corolla lobes, and stamens; Hintonia can be separated by its caducous stipules, solitary flowers, and capsules that are not flattened.

Coutarea was studied in detail by Ochoterena-Booth (1994), who recognized three species. Not all authors have recognized all of these, in particular Coutarea alba has sometimes been synonymized with Coutarea hexandra. Two more species were described by Taylor et al. (2010).

C.M. Taylor II 2012

Distribution: Coutarea has its center of distribution and diversity in dry or seasonal vegetation in Andean valleys and the western Amazon basin of Peru and southern Ecuador. However one species, Coutarea hexandra, is widely distributed from Mexico to Bolivia and southern Brazil (though not in the Antilles; similar plants there belong to Catesbaea, Portlandia, and Cubanola), where it is found in seasonal vegetation but also ranges rather extensively into wet lowland forests.
References:

 

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Coutarea Aubl.

Trees or shrubs, terrestrial, unarmed, sometimes with short-shoots. Leaves opposite, petiolate, venation not lineolate; stipules interpetiolar and sometimes shortly united intrapetiolarly, generally imbricated in bud, persistent, triangular, acute. Inflorescence terminal, cymose, bracteate, 3--15-flowered. Flowers pedicellate, large, showy, homostylous, protandrous. Hypanthium ellipsoid to turbinate. Calyx limb deeply lobed, lobes 5 to 7, linear or lanceolate-setaceous, without calycophylls; corolla funnelform to tubular or weakly inflated, sometimes weakly zygomorphic, white, pink, lavender, purple, or red sometimes marked with cream or suffused with white or pale green, internally glabrous, lobes 5 to 7, imbricate in bud. Stamens 5 to 7, inserted at the base of the corolla tube, asymmetrical due to the filaments curving and twisting to position the anthers together on the lower side of corolla; anthers narrowly oblong, dorsifixed near base, included or exserted. Ovary 2-locular; ovules numerous in each locule, on axile placentas. Fruit capsular, obovoid to ellipsoid, strongly flattened perpendicular to septum, chartaceous to woody, septicidal from the apex then loculicidal. Seeds small, flattened, elliptic, papery, broadly winged.

 

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Key to Species of Coutarea

1. Corollas zygomorphic, curved in the tube, white to pink, with tube funnelform, 19-60 mm long; anthers exserted.

     2. Fruit reddish brown, with lenticels well developed, numerous, and circular; dry forests in South America....Coutarea alba

     2'. Fruit gray to brown or black, without lenticels or these few and elliptic; wet to seasonal forests, Mexico to Argentina...Coutarea hexandra

1'. Corollas actinomorphic, straight in the tube, white to pink or red, with tube tubular to funnelform or weakly inflated, 16-20 mm long; anthers partly to completely included.

     3. Corolla funnelform, white to pink, with tube 12-16 mm wide at mouth (on dried specimens)....Coutarea coutaportloides

     3'. Corolla tubular to tubular-funnelform or weakly inflated, red, with tube 3-7 mm wide at mouth (on dried specimens).

          4. Corolla tubular-funnelform to weakly inflated, with tube 4-7 mm wide at mouth; calyx lobes 5....Coutarea andrei

          4'. Corolla tubular, with tube 3-4 mm wide at mouth; calyx lobes 7.....Coutarea fuchsioides

 
 
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