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Published In: Histoire des Plantes de la Guiane Françoise 1: 154, pl. 59. 1775. (Jun-Dec 1775) (Hist. Pl. Guiane) Name publication detailView in BotanicusView in Biodiversity Heritage Library

Project Name Data (Last Modified On 10/2/2009)
Acceptance : Accepted
Project Data     (Last Modified On 7/21/2016)

Ronabea Aubl. includes three neotropical species of low shrubs found in wet forests and gallery forests from Belize to Amazonian Brazil. Ronabea has opposite leaves; raphides in its tissues; narrowly triangular, persistent, interpetiolar stipules; shortly cymose to subcapitate, few-flowered, axillary inflorescences with bracts; sessile, small, distylous flowers; white salverform corollas with five valvate lobes; bilocular ovaries with the basal ovules solitary in each locule; rather small, purple-black, drupaceous fruits; 2 unilocular pyrenes that are smooth on the adaxial surface and open by a preformed ventral lid; and oily endosperm (Taylor, 2004).

In spite of its small number of species, Ronabea has a rather complicated nomenclatural history as summarized by Taylor (2004). In particular R. latifolia is a rather frequently encountered species with a notable amount of morphological variation, especially in leaf size, shape, and pubescence, degree of expansion of the inflorescences, and corolla size, and it has received several different names. Here this species is circumscribed broadly, pending detailed future studies that will need to include field work.

Ronabea has long been considered closely related to or synonymous with Psychotria L., though a few authors have recognized it as a separate genus of Psychotrieae (e.g., Bremekamp 1934). Ronabea species were anomalous in Psychotria in their oily endosperm and also their combination of axillary inflorescences (i.e., borne in both axils at each node), persistent triangular stipules, and blue-black rather than red fruits. One study using molecular systematic data (Piesschaert et al., 2000) found Ronabea to be related to Lasianthus Jack. Ronabea has been most recently recognized as a separate genus of Lasiantheae (Taylor, 2004).

Author: C.M. Taylor. The content of this web page was last revised on 19 November 2010.
Taylor web page: http://www.mobot.org/MOBOT/Research/curators/taylor.shtml


Neotropics: wet lowland forests and gallery forests from Belize to Amazonian Brazil.



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Ronabea Aubl.
 Hist. pl. Guiane 1: 154, t. 59 (1775). --- Type: Ronabea latifolia Aubl.
            Psychotria sect. Oppositiflorae Benth. & Hook., Gen. pl. 2: 124 (1873). --- Type: Psychotria axillaris Willd., nom. illeg., based on Ronabea latifolia Aubl.
            Mapouria sect. 1, "Eumapouria" [≡ Mapouria] ser. 1, C, Axillares Muell. Arg., Fl. bras. 6(5): 385--386, 410--411 (1881).
Terrestrial shrubs or subshrubs, with raphides. Leaves paired, petiolate; blades generally elliptic, without domatia in vein axils, venation weakly to markedly brochidodromous; stipules persisting with the leaves, interpetiolar to very shortly united around the stem, narrowly triangular to subulate. Inflorescences axillary (i.e., present in both axils of a node), subcapitate to congested-cymose, bracteate. Flowers sessile, at least sometimes distylous; hypanthium generally turbinate; calyx limb relatively reduced, 5- lobed; corolla salverform, white, straight in tube, lobes 5, valvate, smooth abaxially; stamens 5, inserted in corolla tube; anthers narrowly oblong, dorsifixed near middle, included; stigmas 2, generally linear, in long-styled flowers exserted, in short-styled flowers included; disk annular to bilobed; ovary bilocular; ovules solitary in each locule, basal. Infructescences similar to inflorescences. Fruits drupaceous, generally ellipsoid, carnose, blue to black; pyrenes 2, unilocular, hemispherical in cross-section (i.e., planoconvex), dorsally (i.e., abaxially) and ventrally (i.e., adaxially) smooth, opening by preformed ventral lids.
            Three neotropical species, Belize to south-central Brazil.

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Key to Species of Ronabea
1. Stems and leaves, at least adaxially, pilose to hirsute...R. isanae
1. Stems and leaves glabrous to hirtellous or strigillose.
     2. Leaves 7-15 x 2-6 cm, drying membranaceous to papyraceous; calyx limb lobed for more than 1/2...R. emetica
     2. Leaves 6-20 x 3-10 cm, drying stiffly papyraceous to chartaceous; calyx limb lobed for less than 1/4...R. latifolia
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