Anatomia foliar, morfologia e aspectos ecológicos das espécies da família Amaranthaceae da Reserva Particular do Patrimônio Natural Cara Preta, em Alto Paraíso, GO, Brasil

Abstract

Abstract:The Amaranthaceae family is composed of 2,360 species of which 145 are found in Brazilian vegetation. About 94 species of this family subsist in different phytofisionomies of the Cerrado Biome (a savanna-like vegetation) and 27 species are cited in Brazilian regional lists of endangered species. This work aimed to inventory and to study the leaf anatomy and morphology of the Amaranthaceae species found in one Conservation Area in Alto Paraíso, GO, relating them to the species' photosynthetic metabolism. It was found one subshrub species (Pfaffia townsendii) and five herbaceous species (Froelichiella grisea, Gomphrena hermogenesii, G. lanigera, G. prostrata and P. gnaphalioides), most of them showing pirophytic and anemocoric behavior and well developed subterraneous systems associated with leaf amphistomy. The Kranz anatomy was verified in three species (all Gomphrena genus), which indicates the C 4 pathway of photosynthesis. Two species are endemic of the area (Chapada dos Veadeiros) and two are considered endangered species. The anatomy and morphology aspects are discussed in relation to the species habit, ecological behavior, life span of the aerial organs and functional data. The results indicate the Amaranthaceae importance as biodiversity indicator of open vegetation areas of Cerrado and the necessity of further research in Chapada dos Veadeiros, which has the potential to register new plant species, including endemic ones, since this work displays the seasonal behavior of some dicotyledonean herbaceous species and the difficulties to locate, identify and collect them. Resumo: A família Amaranthaceae é formada por cerca de 2.360 espécies, 145 delas encontradas no Brasil. Cerca de 94 espécies da família subsistem em diversas fitofisionomias do Bioma Cerrado e 27 espécies aparecem em listas regionais de espécies ameaçadas de extinção. O objetivo deste trabalho foi inventariar e estudar a anatomia foliar e a morfologia de espécies da família Amaranthaceae de uma Unidade de Conservação de Alto Paraíso, GO, relacionando-as ao metabolismo fotossintético. Foram localizadas uma espécie de hábito subarbustivo (Pfaffia townsendii) e cinco espécies herbáceas (Froelichiella grisea, Gomphrena hermogenesii, G. lanigera, G. prostrata e P. gnaphalioides), a maioria demonstrando comportamento pirofítico e anemocoria, bem como sistemas subterrâneos bem desenvolvidos associados com anfiestomia foliar. A anatomia Kranz foi caracterizada em três espécies (todas do gênero Gomphrena), indicando o metabolismo fotossintético C 4 . Duas espécies são endêmicas da área e duas espécies são consideradas ameaçadas de extinção. Aspectos de anatomia e morfologia são discutidos em relação ao hábito das espécies, comportamento ecológico, duração das porções aéreas e significado funcional. Os dados demonstram a importância da família como indicadora da biodiversidade das áreas abertas dos cerrados e da importância da ampliação das pesquisas na Chapada dos Veadeiros, que tem potencial para o registro de novas espécies, inclusive end...

Plant Structure in the Brazilian Neotropical Savannah Species

“…Using only data obtained about perennial species, an interesting case is the aerial life cycle of Froelichiella grisea, which is endemic of the rocky fields of Chapada dos Veadeiros, Goiás State [34]; this species was registered during the onset of the flowering stage in the field, almost after two years of searching for it, only 20 days after a fire that burned out the vegetation (in August, during the dry season); Gomphrena lanigera Pohl ex Moq. also was found only at the same day, at the fruiting stage, revealing an even faster life cycle of the aerial parts [48,57]. On the other hand, the species Pfaffia townsendii and G. hermogenesii J.C. Siqueira were found in the same region all year round; whilst the first one was always bearing flowers (it is a well-branched shrub that stands out in the middle of the rocks), the second one was usually found in the vegetative stage, more or less hidden among the surrounding Gramineae (=Poaceae) and Cyperaceae; only after the fire grazed all the grasses of the area, G. hermogenesii re-sprouted its aerial organs and was found in the onset of the flowering stage [48,57].…”

“…also was found only at the same day, at the fruiting stage, revealing an even faster life cycle of the aerial parts [48,57]. On the other hand, the species Pfaffia townsendii and G. hermogenesii J.C. Siqueira were found in the same region all year round; whilst the first one was always bearing flowers (it is a well-branched shrub that stands out in the middle of the rocks), the second one was usually found in the vegetative stage, more or less hidden among the surrounding Gramineae (=Poaceae) and Cyperaceae; only after the fire grazed all the grasses of the area, G. hermogenesii re-sprouted its aerial organs and was found in the onset of the flowering stage [48,57]. Another species, G. arborescens is usually found at bloom time at RECOR/IBGE and at the Olympic Center of Universidade de Brasília, in Brasília, Federal District, during the rainy station (from November to April) and at vegetative stage from August to October (during winter); in this 0.5 meter high species, leaves were always attached to the shoot at the same time as the flowers and fruits, although in the end of the fruiting stage, some or all the shoots bearing fruits can dry out, in order to release the fruits [58].…”

“…Species' survival in adverse environments can be achieved by the operation of C 4 photosynthesis and carbon accumulation [109], which is associated with high photosynthesis rate [74]; the accumulated carbon is stored and protected in the underground organs, explaining the energy source to re-sprout of Cerrado species. Although in [92] trichomes are believed to affect the gas exchange and leaf temperature, reducing the light incidence, Gomphrena arborescens developed a translucid tissue surrounding the large trichome bases, which allows the light to reach internal photosynthetic tissue [26], indicating that its trichomes can be more a restriction to herbivory than to reduce leaf temperature or light incidence, the same way as in G. pohlii and G. virgata [58]; another aspect shared by all Amaranthaceae Cerrado´ species is the constant presence of calcium oxalate druses inside leaves and shoots [26,47,[57][58], which is considered a highly specialized way of sequester and immobilise calcium [110]. Large plastoglobuli were found in chloroplasts F. grisea, G. arborescens, G. hermogenesii, G. pohlii and G. virgata.…”

Amaranthaceae as a Bioindicator of Neotropical Savannah Diversity

“…Five of these species had never been recorded in this RPPN before and one of them was last recorded in 1966 (F. grisea), according to Herbaria data. Figures 1-8 are reproduced [77] with the authorization of the Biota Neotropica Editor, Dr. Carlos Joly. (Figures 1-8) Photographs of the environment and of the studied species at Reserva Particular do Patrimônio Natural (RPPN) Cara Preta, Alto Paraíso, Goiás State, Brazil.…”

“…Figures 9-14 [77] were reproduced with the authorization of the Biota Neotropica Editor, Dr. Carlos Joly.…”