Siparunaguianensisis an early secondary successional species of which individuals are monoecious (male and female reproductive parts on same plant) shrubs or small trees up to 15m high reaching a diameter of breast height of 20cm.Leaves are simple,opposite, membranous, petiolate (have petioles), and have smooth margins. Inflorescences are axillary (developing in the axil as opposed to apex) and fasciculate (clustered). Flowers are unisexual and pedicellate (having short pedicels, or floral stalks) with a cup-shaped receptacle (top or flower stalk = basal part of flower) completely covering the carpels or stamens until anthesis (when flower fully opens and becomes functional). Mature fruits are aggregate fleshy, globose (spherical), pubescent with stellate (star-shaped) trichomes, and 0.7 to 1.4 cm in diameter. New and mature fruits are red-green and exude strong, unpleasant, citrusy odor with a yellow interior containing 4-10 seeds (Renner & Hauser 2005). The fruits are zoochorous (seeds dispersed by animals) with a sweet aril (Goncalves et al. 2015).
Nicaragua throughout northern South America to Paraguay. Primary and secondary forests up to 1200m, rarely 1400m (Renner & Hausner 2005).
Habitat
Siparuna guianensis is found in mainly understory and regeneration areas on both edge and inner forest fragments (Goncalves et al. 2015). Because it is an understory secondary successional species, S. guianensis has a few adaptations for fast growth in low-light conditions. Seedlings and saplings have been observed to invest more energy into height than into thickness of leaves or spongy parenchyma in the woody stem (Viera et al. 2015).
Pollination
Siparuna guianensisis pollinated at night by gall midges (Diptera: Cecidomyiidae) (Renner & Hausner 2005).
Fruiting and dispersal
Fruits are ripe at the end of the rainy season and the beginning of the dry season, between December and April (Goncalves et al. 2015)). Individuals produce many fruits at a time, each with many seeds, to attract more dispersers. (Francisco and Galetti, 2002). The main dispersers are birds like Antilophia galeata, Dacnis cayana, Lanio penicillatus (Goncalves et al. 2015) and from the families Ptilogonatidae and Tyrannidae (Valentini et al. 2010). S. guianensis fruit were consumed by individuals of different feeding guilds and habitat use, which can contribute to the success of species in regenerating environments by being less selective towards dispersers, thus increasing the chances of effective seed dispersal (Goncalves et al. 2015).
The only known predispersal seed predator of S. guianensis is the buffy-headed marmoset (Callithrix flaviceps) which targets the seeds for their high carbohydrate, protein, and lipid contents. Because the receptacles of S. guianensis contain high amounts of benzylisoquinoline alkaloids, C. flaviceps wait until the fruit has ripened and the receptacle splits open to expose the seeds. This feeding strategy may have a significant effect on the reproduction of S. guianensis populations in many areas (Simas et al. 2001)
Essential oils derived from S. guianensis have proven to deter oviposition in both species of the mosquitos Aedes aegyptiandCulexquinquefasciatus. The larvicidal effect of the essential oil has been found to be more effective than that of several species of Eucalyptus, another common larvicide for mosquitos. It is also toxic to the tickR. microplus. (Aguiar et al. 2015). In addition to toxicity, the essential oil ofS. guianensis shows repellant activity against the mosquitosA.aegyptiandC.quinquefasciatus. The toxicity and repellant activity ofS. guianensis essential oil shows promise for development of natural insecticides and insect repellants (Aguiar et al. 2015).
Essential oils are also used to treat stomach disorders, malaria, fevers, and colics (Valentini et al. 2010). Flavonoids such as apigenin and kaempferol extracted from the plant are known to be anxiolytics, or anxiety-inhibitors (Negri et al. 2012).
Status: Not threatened (Valentini et al. 2010).
The main oil constituents from the leaves includeβ-myrcene and 2-undecanone. From the stem: β-myrcene, δ-elemene, germacrene D, α-limonene, and bicyclo-germacrene. From the fruit: 2-tridecanone, 2-undecanone, and β-myrcene.
Reports of percentage composition of the oil components of S.guianensisvary, suggesting significant differences in the samples studied. Differences might be due to environmental or genetic differences between populations of S.guianensis (Aguiar et al. 2015).
