Phenakospermum Research Articles

<p><strong>Lectotypification and notes on the distribution of the giant herb <em>Phenakospermum guyannense</em> (Rich.) Miq. (Strelitziaceae)</strong></p>

Phenakospermum guyannense is the only native species of Strelitziaceae in South America and occurs in the Amazon domain in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela. The species presents a negative sampling bias, probably due to the great effort necessary to collect it, as it presents long leaves and coriaceous bracts. In the course of the studies for the monograph of Strelitziaceae for Flora do Brasil 2020 project and with an increase in plant collecting in Maranhão state, Brazil, we have detected two necessary adjustments to the knowledge of the species: 1) lectotypification of the basionym Urania guyannensis described by L.C.M. Richard and 2) reevaluation of the geographic distribution of the species, highlighting new records for the Brazilian Northeast region. Both issues are addressed here. Additionally, we present a description, a preliminary conservation status, a distribution map and notes on the ecology of the species.

Effects of forest succession on the richness and composition of Zingiberales in a forest fragment in the southwestern Amazon

Tropical forests have been increasingly modified by human activities and the forest recovery through succession has caused an increase in the amount of secondary forests in the landscape. Little is known about changes in the richness and composition of non-woody species throughout the succession in tropical forests; therefore, the objective of this work was to evaluate the effects of forest succession on a community of herbs in the order Zingiberales. Zingiberales and soil were sampled and data on vegetation structure, including bamboo abundance, canopy opening, and basal area were collected from nine 80 × 90 m plots installed on the Catuaba Experimental Farm, Acre, representing three successional stages: early secondary forest, late secondary forest, and mature forest. Early secondary forest areas were experimentally deforested, burned, and sprayed with herbicide in the dry season of 2001 and the late secondary forest areas suffered deforestation followed by burning for agricultural cultivation between 1985 and 1986. A total of 3,831 individuals and 26 species distributed in nine genera and five families was registered. Both soil characteristics and vegetation structure variables showed significant differences among the successional stages. The richness of Zingiberales was lower in the early secondary forest areas and did not differ among the other successional stages. Canopy opening was the variable that best explained the variation in the richness of Zingiberales among the areas. The composition of Zingiberales differed among the successional stages, with the late secondary forest and mature forest stages being most similar. The soil characteristics, canopy opening, bamboo abundance and basal area were the variables that best explained a variation in the composition of Zingiberales. In the areas of initial secondary forest the group of dominant species was composed of Renealmia breviscapa, Calathea altissima and Heliconia rostrata, in the areas of late secondary forest by Chamaecostus lanceolatus Calathea polytricha, Calathea sp.1 and in the areas of mature forest by Heliconia acuminata, Calathea mansonis and Phenakospermum guyannense. These results show that the disturbance caused by cutting, burning, and herbicide application alters the community of Zingiberales. These data also highlight the importance of late secondary and mature forests in maintaining and recovering biodiversity.

Relative palatability and growth performance of capoeira species as supplementary forages in the NE-Amazon

In northeastern Pará, smallholder agriculture systems are still based on secondary forest fallows, nationally called “capoeira”, presumed to contain a remarkable amount of underutilized valuable woody species, for instance as supplementary forage for cattle. We tested five promising capoeira species, namely Phenakospermum guyannense, Cecropia palmata, Attalea maripa, Inga edulis, and Abarema jupunba by comparing its relative palatability—i.e., the palatability differences between the tested species and the reference forage legumes, forage grass, and between the other tested species-, heights, biomass production, and main nutritive values with the well-known tropical forage legumes Cratylia argentea and Flemingia macrophylla. Additionally, the locally common domesticated species Tithonia diversifolia, Mangifera indica, and Racosperma mangium were also included in the trial, all implemented in a randomized block design on a Brachiaria-pasture (n=2000 saplings, 8 replication blocks). After two years of establishment, four steers with an average body mass of 506kg browsed the trial (2 AU/ha). The relative palatability testing showed that A. jupunba, M. indica and also surprisingly R. mangium (all >20% of its respective total biomass) matched the consumed biomass of F. macrophylla, while C. palmata (>60%) even surpassed very palatable C. argentea. R. mangium also had the highest biomass production, while the other species showed just regular growth and establishing rates. Protein contents of all species were above 6%, most of them higher than 10% and in the case of T. diversifolia even above 20%. Thus, all tested species almost reached the quality of the reference legumes. However, as plant secondary compounds were not regarded in this trial, recommendations as supplementary forage plants can only be given with reservations. The results suggest that smallholders possess cheap forage supplement alternatives on their farms and even on their pasture plots, which simply have to be tolerated by just pruning them into accessible heights for animals. However, sapling transplantation from shady capoeiras on old slightly degraded pastures for biomass enrichment cannot be recommended.

FLORESTAS ANTRÓPICAS NO ACRE: INVENTÁRIO FLORESTAL NO GEOGLIFO TRÊS VERTENTES, ACRELÂNDIA

O artigo apresenta os resultados do primeiro inventário de um hecta¬re realizado na área de um sítio tipo geoglifo. Até o momento, todos os geoglifos estudados não tinham cobertua vegetal. O geoglifo Três Vertentes não mostra evidência de ter sido queimado ou usado para agricultura ou assentamento no passado recente. Assim, é possível que a vegetação existente sobre o geoglifo não tenha sido perturbada, com a possívele exceção de usos extrativos pela caça ou coleta de látex. Trata-se de uma mata de cipó. Essa conclusão apoia-se na grande proporção de árvores dicotiledôneas cobertas por cipós, com a alta densidade e frequência de moráceas, cuja maior parte é composta por cipós ou trepadeiras. Há grande densidade e frequência de palmeiras excluem cipós, também a alta frequência de bananeiras bravas (Phenakospermum guyannense). Nota-se uma área basal relativamente pequena e o pequeno número de indivíduos com dbh ? 10 cm dentro de um hectare de floresta. É surpreendente o fato de haver uma nova espécie a cada dois ou três in-divíduos com dbh ? 10 cm. A conclusão resultante desses dados é que os engenheiros e construtores oiginais do geoglifo não deixaram como legado pobreza de espécies vegetais e degradação ambiental. Palavras-chave: inventário florestal, arqueologia Amazônica, biodiversidade.

Morfoanatomia e histoquímica da semente de sororoca (Phenakospermum guyannense (Rich.) Endl. - Strelitziaceae)

Phenakospermum guyannense é popularmente conhecida na Amazônia como sororoca, geralmente encontrada próxima a cursos d´água, em ambientes ombrófilos. Objetivou-se com este estudo descrever a morfoanatomia e histoquímica da semente madura de P. guyannense, como contribuição a estudos taxonômicos, fisiológicos e ecológicos. Sementes maduras foram coletadas nas margens da Cachoeira do Urubuí, no Município de Presidente Figueiredo, Amazonas. O estudo anatômico foi realizado conforme técnicas usuais para análise em microscopia óptica e eletrônica de varredura. Foram aplicados testes histoquímicos para a detecção de compostos fenólicos, amido, proteína e lipídios. A semente madura de P. guyannense é estenospérmica, com envoltório de cor negra, formado por vários estratos de diferentes tipos celulares, sendo a maioria impregnada de compostos fenólicos. O hilo é punctiforme, circundado por células que constituem o arilo. O endosperma é sólido, constituído por células tetraédricas de conteúdo amiláceo e proteico. O embrião é basal capitado, apresentando células de conteúdo lipídico e proteico, composto por eixo hipocótilo-radícula levemente dilatado de forma cilíndrica e localiza-se na região proximal. O haustório apresenta formato aplanado e situa-se na região distal.

Description of Culicoides (Mataemyia) felippebauerae sp. n., Forcipomyia musae immatures, and occurrence of F. genualis, breeding in banana stems in Brazilian Amazonia (Diptera: Ceratopogonidae)

The following three species of Ceratopogonidae were collected breeding in the rhizomatous herb Phenakospermum guyannense Endl., 1833 in the vicinity of Manaus, Brazil, a new species, Culicoides (Mataemyia) felippebauerae Spinelli, Forcipomyia (Forcipomyia) genualis (Loew), and F. (Phytohelea) musae Clastrier & Dellécole. C. (M.) felippebauerae is described and illustrated as adult, pupa, and fourth instar larva, the adult compared with the adult of C. barthi Taveres and Souza and larva and pupa with those of C. dicrourus Wirth & Blanton and C. macieli Tavares & Ruiz, the only species with known immatures in the subgenus. The pupa and fourth instar larva of F. (P.) musae are described and illustrated and compared with immatures of F. (P.) edwardsi Saunders.

Description of Culicoides (Mataemyia) felippebauerae sp. n., Forcipomyia musae immatures, and occurrence of F. genualis, breeding in banana stems in Brazilian Amazonia (Diptera: Ceratopogonidae)

The following three species of Ceratopogonidae were collected breeding in the rhizomatous herb Phenakospermum guyannense Endl., 1833 in the vicinity of Manaus, Brazil, a new species, Culicoides (Mataemyia) felippebauerae Spinelli, Forcipomyia (Forcipomyia) genualis (Loew), and F. (Phytohelea) musae Clastrier & Dellécole. C. (M.) felippebauerae is described and illustrated as adult, pupa, and fourth instar larva, the adult compared with the adult of C. barthi Taveres and Souza and larva and pupa with those of C. dicrourus Wirth & Blanton and C. macieli Tavares & Ruiz, the only species with known immatures in the subgenus. The pupa and fourth instar larva of F. (P.) musae are described and illustrated and compared with immatures of F. (P.) edwardsi Saunders.

Ecological Observations on Heteropsis Spp. (Araceae) in Southern Venezuela

This article contributes a brief review of the ethnobotany and ontogeny of Heteropsis spp. (Araceae), reports the distribution and density of Heteropsis spp. in a tropical lowland rainforest in southern Venezuela, and explores the environmental variables that correlate best with the observed Heteropsis densities. Heteropsis occurred on 26% of the 4091 trees (≥10 cm DBH) inventoried in 67 plots (of 0.1 hectare, each). Mean Heteropsis colonization densities differed significantly between 11 local forest types and ranged from 0% (in seasonally deeply flooded forest and in semideciduous hill forest) to 74% (in sporadically flooded forest near small streams). Across forest types, Heteropsis occurred on a significantly greater number of trees between 20 and 50 cm DBH than expected for an even distribution over all size classes. Of the 90 most common potential host species in the plots, the giant herb Phenakospermum guyannense (L. C. Rich.) Endl. was the only one consistently and significantly avoided by Heteropsis, and no host species was significantly preferred across all forest types. Heteropsis densities were positively correlated with the depth of the fine root mat and the diversity of big lianas. They were negatively correlated with the concentration of exchangeable potassium, flooding depth, and the density of small lianas. We conclude that Heteropsis shows clear habitat preferences that reflect site differences in soil fertility, flooding regime and forest structure and could not be explained by the distribution of preferred or avoided host tree sizes or species.

Shape Matters: Hofmeister’s Rule, Primordium Shape, and Flower Orientation

Hofmeister's rule is an empirical heuristic derived from the observation that new leaf primordia are formed in the largest space between the existing flanks of the older primordia. These observations have been repeatedly validated in studies of leaf arrangement, but there has been little attempt to extend them to inflorescence and floral organs. This investigation demonstrates the validity of Hofmeister’s observations to cincinnus and early flower development in Phenakospermum guyannense (Strelitziaceae) and Heliconia latispatha (Heliconiaceae) and relates these results to Paul Green’s work on the biophysics of organ formation. The cincinni of Phenakospermum and Heliconia arise in the axils of primary bracts and produce a prophyll, continuation apex, and flower in regular succession. The shapes and orientations of the apical regions of the cincinni are correlated with the placement of these organs, which in turn effect the positions of the sepals and their sequence of formation. The result is two rows of mirror‐image flowers. The mirror‐image symmetry of the flowers is a direct result of Hofmeister’s rule in connection with the shape of the apical region. These two factors create a self‐sustaining developmental system that produces prophylls, continuation apices, flowers, and sepals in regular succession. Although the cincinni and flowers of these species are built on a common plan, slight differences in apical shape and orientation produce differences in mature floral orientation. Understanding these orientations, and identifying the sequence of sepal formation, allows a proper identification of organ homologies. A study of Green’s results and theories shows that Hofmeister’s rule can be considered as an empirical condensation of the biophysical factors that influence organ position. These biophysical factors are widely applicable to organ formation in many species.

Spectral irradiance and stomatal conductance of enriched fallows with fast-growing trees in eastern Amazonia, Brazil

The biomass production of both indigenous and introduced plant species in tropical fallow systems depends on the degree to which these species can acclimate to the light and water environments. Results for light spectral composition monitoring within the canopy of enriched fallows and for the leaf stomatal conductance of fast-growing leguminous trees and indigenous fallow species are presented. All measurements were made in a smallholder farm in Igarape- Acu, northeastern Para State, Brazil. Light spectral composition (330 to 1100 nm) was moni- tored at two heights (ground level and 1 m) in a six-year-old natural fallow, 1.5-year-old natural fallow, and 1.5-year-old fallows enriched with Acacia angustissima, Acacia mangium, Clitoria racemosa, Inga edulis, Sclerolobium paniculatum, and a mixture of these trees. Light-quality parameters including photosynthetically active radiation, phytochrome active radiation, and blue active radiation changed most drastically in the stands enriched with A. mangium. Stomatal conductance was higher for A. mangiumthan the other trees and four common indigenous fallow vegetation species (Phenakospermum guyannense , Davilla rugosa, Lacistema pubescens, and Myrcia bracteata). Results suggest that the enrichment of fallows with A. mangiummay promote changes in light and water vapor exchange regimes, with potential effects on species diversity in fallows.

Rainfall partitioning and related hydrochemical fluxes in a diverse and in a mono specific (Phenakospermum guyannense) secondary vegetation stand in eastern Amazonia.

Rainfall partitioning into throughfall and stemflow was studied in a diverse and in a mono specific stand of secondary vegetation in Eastern Amazonia. The nutrient concentrations in the water were analysed in order to quantify the related hydrochemical fluxes. Secondary vegetation forms the fallow in the local shifting cultivation system and is usually dominated by shrubs and trees. Phenakospermum guyannense (Strelitziaceae), a banana-like herb, is one of the predominant non-woody species. The study was conducted during an 18-month period in a 2.5-year-old relatively species-rich stand and a 10-year-old stand dominated by P. guyannense. In a year with 1956 mm of rainfall 65% (1281 mm) of this quantity reached the soil as throughfall in the diverse stand and 38% (743 mm) in the mono specific stand. Stemflow was estimated to be 23% and 41% respectively. P. guyannense and Banara guianensis (Flacourtiaceae), a tree species, were causing these high funnelling effects. In the young diverse stand B. guianensis had a stemflow of more than 200 l year-1 and P. guyannense had a median flux of 77 l year-1 per pseudostem. In the older stand the taller plants of P.␣guyannense collected 644 l year-1 per pseudostem on the median. The reason for these high values could be the banana-like growth form of P. guyannense and the crown morphology of B. guianensis, which has inclined branches. The low proportion of throughfall and the high stemflow values differ from all previous studies in Amazonian primary forests. The proximity to the Atlantic Ocean strongly influenced the nutrient fluxes via rainfall at our study site. This becomes obvious from the high Na and Cl fluxes with rainfall (19.7 kg Na ha-1 year-1, 37.2 kg Cl ha-1 year-1) which were approximately equal to the Na and Cl fluxes with the sum of throughfall and stemflow for both stands. K fluxes in throughfall and stemflow in both stands were higher than in rainfall by a factor of 8. The high K enrichment during the crown passage is assumed to be caused by a␣high K concentration in the leaf tissue resulting in enhanced leaching from the leaves. In months with low␣rainfall the concentrations of Ca, Mg, S and Cl in throughfall of the diverse stand were significantly higher than in months with high rainfall. This was mainly due to vegetation burns in the dry period, which resulted in ash deposition on the canopy and subsequent wash-off and solution of ash particles.

Low levels of genetic variation inPhenakospermum guyannense (Strelitziaceae), a widespread bat-pollinated Amazonian herb

Phenakospermum guyannense is a monotypic, arborescent, long-lived monocot that is widespread in Amazonian South America. This outcrossing species is pollinated primarily by phyllostomid bats. Given these life-history characteristics,P. guyannense is expected to exhibit high levels of genetic variation and gene flow. We used isozyme electrophoresis and randomly amplified polymorphic DNA (RAPD) to characterize genetic variation in populations ofP. guyannense from French Guiana. Both measures detected a surprisingly low level of genetic variation, with only five out of twenty (25%) allozyme loci polymorphic (P), 1.35 alleles per locus (A), and an expected heterozygosity (He) of 0.090 at the species level. Isozymic genetic variation was even lower within populations (P = 17.5, A = 1.24, He = 0.074), and was corroborated by a RAPD assay that used 26 arbitrary primers (P = 3.61, A = 1.04, He = 0.014). Although overall levels of variation were low, the detectable variation was distributed as would be expected for an outcrossing species with extensive gene flow (mean GST = 0.230). We suspect thatP. guyannense is depauperate in genetic variation because of a series of bottlenecks that affected the species over this portion of its range.