Papers by Igor Soares dos Santos
Flora, 2023
Cyrtopodium comprises 50 species, 37 of which are found in Brazil, with 19 being endemic. Some of... more Cyrtopodium comprises 50 species, 37 of which are found in Brazil, with 19 being endemic. Some of the Brazilian species are morphologically similar, with similar life forms, and are often confused in herbarium collections. We tested whether the anatomical characters of the vegetative systems of eight species of the genus occurring in savanna areas of Central Brazil could be used to differentiate them, or if those differences reflect environmental conditions. We found that: i) the studied species can be differentiated by leaf characters (e.g., the types and locations of their epicuticular waxes and cuticle ornamentations, the presence or absence of prismatic crystals and trichomes, midrib contour, composition and orientation of the leaf margin, numbers and arrangements of the vascular bundles), by pseudobulb characteristics (e.g., the shapes of the subepidermal cells), and by radicular characteristics (e.g., numbers of cortex and velamen layers, the presence or absence of trichomes, phi thickening, spiral idioblasts, the numbers of protoxylem poles); and that, ii) the thick cuticle of the pseudobulb, the density of waxes, and the presence of supra- and substomatal chambers in the leaves, as well as tilosomes and the numbers of layers of velamen in the roots, may reflect adaptations to environmental conditions and life forms. Additionally, we report here for the first time for the genus, the presence of crystals in epidermal cells, striae and epicuticular waxes, root trichomes, phi thickening, and spiral idioblasts, and describe the ascending and tangled "trash-basket" roots of C. saintlegerianum in an ecological-functional context associated with epiphytism.
Anatomy and histochemistry of the vegetative system of Brachystele guayanensis (Lindl.) Schltr. (Orchidaceae), a potential medicinal species, 2023
The orchid genus Brachystele Schltr. (Orchidoideae, Cranichideae, Spiranthinae) comprises 20 spec... more The orchid genus Brachystele Schltr. (Orchidoideae, Cranichideae, Spiranthinae) comprises 20 species distributed from Mexico to Argentina, with 10 species found in Brazil. Anatomical studies of Orchidoideae Lindl. have been scarce, and the anatomy and histochemistry of Brachystele are still largely unknown. In this study, we conducted a characterization of the vegetative organs of B. guayanensis (Lindl.) Schltr. using standard anatomical and histochemical microtechniques. In this study, we provide the first information about the anatomy and histochemistry of Brachystele. The studied species was observed to display anatomical characters commonly found in the vegetative organs of representatives of the Cranichideae tribe (e.g., uniseriate epidermis; homogeneous mesophyll with 6–11 layers; rhizomes with rings of fibers; vascular bundles in the form of “^” or “v”; fleshy roots with uniseriate velamen, simple trichomes, and spiranthosomes). Others can be interpreted as adaptive strategies conditioned by the environment and their terrestrial life form (e.g., cuticle thickness; amphistomatic leaves; roots with reduced velamen compared to the cortex (18–20 layers); and raphides). In this study, cataphylls, and the presence of spiranthosomes in leaves, including stomatal guard cells, as well as alkaloids in these structures, are anatomically described for the first time in Orchidaceae. The presence of hyphae and pelotons in the stem of B. guayanensis is described for the first time in Cranichideae. Histochemical tests confirmed the presence of lignin, proteins, and alkaloids, the lipidic nature of the cuticle, starch grains stored in spiranthosomes, and the composition of the raphides. Alkaloids were observed in abundance, particularly in the roots, suggesting a potential role in defense against pathogens and herbivores, as well as potential medicinal activities, as seen in phylogenetically related groups to Brachystele.
Hoehnea
RESUMO Campylocentrum Benth. possui distribuição neotropical e cerca de 73 espécies arranjadas em... more RESUMO Campylocentrum Benth. possui distribuição neotropical e cerca de 73 espécies arranjadas em cinco seções. No Brasil, está representado por 38 espécies (24 endêmicas), concentradas, sobretudo, na Mata Atlântica. Com intuito de contribuir com o conhecimento taxonômico do gênero em áreas de Cerrado do Brasil Central, onde o mesmo não é estudado, fornecemos um tratamento taxonômico às espécies ocorrentes no Distrito Federal e no Estado de Goiás. Foram registrados cinco taxa arranjados em três seções: C. kuntzei Cogn. ex Kuntze, C. mattogrossense Hoehne (C. sect. Campylocentrum Cogn.), C. neglectum (Rchb. f. & Warm.) Cogn. (C. sect. Laevigatum E. Pessoa & M. Chase), C. fasciola (Lindl.) Cogn. e C. pachyrrhizum (Rchb. f.) Rolfe (C. sect. Dendrophylopsis Cogn.). Destes, C. fasciola constitui uma nova ocorrência para a flora de Goiás. São apresentados uma chave de identificação, descrições, comentários taxonômicos e de distribuição geográfica, além de imagens e ilustrações.
Phytotaxa
Davilla pygmaea, a new species endemic to the Brazilian Savanna, is described, illustrated and it... more Davilla pygmaea, a new species endemic to the Brazilian Savanna, is described, illustrated and its systematic position is discussed here. The new species is closely related to D. elliptica and D. grandiflora, from which it differs by characters such as a decumbent habit, the shape of its leaf blades, the inflorescence architecture, the size and numbers of flowers, the size of the internal and external sepals during flowering and fruiting, the androecium with 126-131 stamens, and the presence and type of trichomes on vegetative organs. Anatomical characters such as the number of vascular bundles in the petiole and midrib, shape of the midrib in cross section, the margins of the leaf blades, the presence and arrangement of the fibers associated with small-caliber vascular bundles, and the presence of a fiber sheath extension in studied species also differentiate them. Histochemical tests demonstrated that alkaloids, acidic lipids, and phenolic compounds present in the leaf tissues of ...
Phytotaxa
A new species of Copaifera from a diversity hotspot in the Brazilian Cerrado is described. Copaif... more A new species of Copaifera from a diversity hotspot in the Brazilian Cerrado is described. Copaifera appendiculata M.J. Silva appears to be endemic of the northern portion of Goiás State, Brazil, and its conservation status is classified as Critically Endangered. It is a dwarf species and can be recognized by a set of characteristics that include: foliar rachis spiny and conspicuously prolonged (the first such report for the genus), leaflets similar in size, usually glabrescent on both surfaces, with planar margins, with discreet or conspicuous translucent points, sepals indumented on both surfaces, fruits glabrous, and seeds with an orange aril. It is compared with similar dwarf species of the genus present in the Cerrado, especially with Copaifera marginata, its closest congener. Also furnished are illustrations, images, information concerning its flowering and fruiting seasons, geographical distribution, as well as preliminary conservation assessments. Examinations of the leaf an...
FIGURE 4. Leaf architecture of Phyllantus pterocaulis. A. Adaxial surface of the leaf blade; B an... more FIGURE 4. Leaf architecture of Phyllantus pterocaulis. A. Adaxial surface of the leaf blade; B and E. abaxial surface of the leaf blade; C. Border with non-glandular trichomes; D. Non-glandular trichomes on adaxial surface; F. Stomata. Arrows indicate anomocytic (1), and paracytic stomata (2). Scale bars (A, B = 1000 µm, C–E = 200 µm, F = 50 µm).
FIGURE 1. Phyllanthus pterocaulis M.J. Silva. A. Habit; B. Portion of branch, note the winged pro... more FIGURE 1. Phyllanthus pterocaulis M.J. Silva. A. Habit; B. Portion of branch, note the winged projections and hispidulous trichomes; C. Stipules; D. Leave, note the ciliate margin; E. Detail of lower side of the leaf blade showing trichomes; F. Detail of the bisexual cymules. G. Staminate flower; H. Pistillate flower in frontal view; I. Pistillate flower, note the disk and ovary; J. Fruit; K. Mericarps removed showing the carpophorous; L. Seed, lateral view; M. Seed, dorsal view. (drawings by Cristiano Gualberto, from the holotype)
Phytotaxa, 2020
Analysis of Brazilian collections and foreign herbaria, specially of those from the Midwest regio... more Analysis of Brazilian collections and foreign herbaria, specially of those from the Midwest region of Brazil for taxonomic studies on Chamaecrista sect. Absus subsect. Absus developed by the authors, resulted in a discover a new species. Chamaecrista barnebyana is here described, illustrated, and commented on its distribution, conservation assessment, including environmental preferences, flowering and fruiting, and position systematic. Additionally, it is compared with morphologically similar species using macro-morphological and foliar anatomy characteristics.
Introduction: Infraorder Platyrrhini is composed of species with complex social structures, but i... more Introduction: Infraorder Platyrrhini is composed of species with complex social structures, but information about their interaction with death is scarce in the literature, as already registered for old world monkeys. This work concern of death avoidance behavior recorded in a group of Callithrix penicillata (E. Geoffroy, 1812) (Primates, Callitrichidae). Material and Methods: This is a study made it through opportunistic observation of an interaction between a mother and her cub, accidentally injured and on the deathbed. The detailed description of the phenomenon occurred through all occurrence sampling, and was counted on the testimony of local residents. For better data exposure, an etogram was constructed, containing all the observed behaviors, in sequence, from the beginning to the end of the sampling. Results: In all, 10 individuals participated in the observations, and 16 behavioral acts were observed during 6 days of observation of the interaction mother-child injured-other individuals. The behaviors indicated a high degree of stress on the part of all involved, as well as the mother's attempt to withdraw her cub from the area in which was. The mother also tried to bring it to your back. There were other individuals in the group, possibly to assist in caring for the cub. Conclusion: This work is unpublished for the specie in question and reaffirms its social character. The observations open spaces for further investigation into similar behaviors in human and non-human primates as well as the phylogenetic relationship between them.
<i>Phyllanthus pterocaulis</i> M.J. Silva, <i>sp. nov.</i> (Figs 1, 2) Ty... more <i>Phyllanthus pterocaulis</i> M.J. Silva, <i>sp. nov.</i> (Figs 1, 2) Type:— BRAZIL. Goiás: Niquelândia, Reserva Particular de Desenvolvimento Sustentável Legado Verdes do Cerrado, Núcleo Engenho, Área do Coimbra, imediatamente após a plantação de soja, lado direito da estrada sentido Vila da Reserva, Borda de Floresta Estacional, solo argiloso, 14º33'12"S, 48º31'12"W, 569 m. a.s.l., 19 February 2021, fl., fr., <i>M</i> <i>.J. Silva, I.S. Santos &amp; B.S. <i>Pereira 11935</i> (holotype UFG!, isotypes UB!, CEN!, NY!, RB!).</i> <b>Diagnosis</b>:—This species can be differentiated from its most similar species (see table 1) by having herbaceous habit up to 13 cm tall, stem short and sparsely hispidulous, conspicuously winged in cross section, Leaves ovate with margin irregularly serrate, base truncate or cordate, hispidulous below; flowers on both sexes 5 or 6-merous, the staminate ones with three free stamens, the pistillate ones with bilobed stigma. <b>Description</b> —Herbs 7–13 cm tall, annual, monoecious; stem short and sparsely hispidulous, greenish to green brownish, conspicuously winged in cross section, monopodial or simpodial, with non phyllantoid branching; lateral branches, angulate, striated longitudinally, 2–9.5 cm long, distically distributed. Cataphylls absent. Stipules 1–1.2 mm long, widely triangular, conspicuously auriculate at base, margin entire. Petiole 0.3–0.4 mm long, cylindrical, hispidulous. Leaf blade 3–6 × 2.9–3 mm, chartaceous, ovate and cordate, base truncate or slightly cordate, apex obtuse, margin irregularly serrate and ciliate by hispidulous trichomes; discolorous, opaque green and glabrous above, dark green and hispidulous below; venation brochidodromous, primary and secondary veins impressed on both surfaces. Cymules bisexual on leaf axils and base of the secondary and tertiary branches, with 1 pistillate flower and 1–3, staminate flowers; bracts widely triangular, conspicuously acuminate. Staminate flowers 0.7–0.8 mm long, pedicel 0.4–0.5 mm long, cylindrical; sepals 5 or 6, 0. [...]
FIGURE 6. Cross sections of the internodes of the stem of Phyllantus pterocaulis. A. General aspe... more FIGURE 6. Cross sections of the internodes of the stem of Phyllantus pterocaulis. A. General aspect; B. Epidermis, cortex and vascular system; C. Non-gladular trichomes (*); D. Hypodermis and ground parenchyma in the cortex. A. Arrow indicates stomata in the epidermis; E. Primary phloem; co—collenchyma, ep—epidermis, hy—hypodermis, me—medula, pa—ground parenchyma, ph—phloem, vb— vascular bundles, t—trichomes, xy - xylem. Asterisk shows sieve tube elements. Scale bars (A = 100 µm, B = 70 µm, C-E = 40 µm).
FIGURE 5. Cross sections of Phyllanthus pterocaulis leaf blade and petiole. A–F. Leaf blade; A, B... more FIGURE 5. Cross sections of Phyllanthus pterocaulis leaf blade and petiole. A–F. Leaf blade; A, B Mesophyll; C. border; D. Non-gladular trichomes (*); E. Idioblasts containing druses; F. Vascular bundle; G. Midrib; H. General aspect of the petiole; I. Epidermis and cortex in the petiole. co—cortex, d—druses, ep—epidermis, pa—ground parenchyma, pp—palisade parenchyma. sp—spongy parenchyma, vb— vascular bundle. Scale bars (A–G, I = 40 µm, B = 70 µm).
FIGURE 3. Phyllanthus pterocaulis M.J. Silva. Distribution map.
FIGURE 2. Phyllanthus pterocaulis M.J. Silva. A. Habit; B. Portion of branch showing the cymules ... more FIGURE 2. Phyllanthus pterocaulis M.J. Silva. A. Habit; B. Portion of branch showing the cymules and fruit; C. Detail of the cymules; D. Staminate flower in frontal view; E. Pistillate flower in lateral view, the sepals green whitish; F. Pistillate flower in upper view, the sepals reddish; G. Fruit; H. Seeds in dorsal and lateral view. Photographs by M. J. Silva.
Key for identification of <i>Phyllanthus</i> sect. <i>Loxopodium</i> spec... more Key for identification of <i>Phyllanthus</i> sect. <i>Loxopodium</i> species occurring in Brazil 1. Stems winged, flattened or angled in cross section; leaves chartaceous............................................................................................2 - Stems cylindrical in cross section; leaves thinly membranaceous.....................................................................................................4 2. Stems up to 13 cm tall, winged, hispidulous; leaves 3–6 × 2.9–3 mm, indumented, ciliate at margin; pistillate disk patelliform; flowers on both sexes 5 and 6-merous on the same plant.............................................................................. <i>Phyllanthus pterocaulis</i> - Stems (15) 19–50 cm tall; subcylindrical, angled or flattened, glabrous; leaves 5–15 × 3–6 mm glabrous, non-ciliate at margin; pistillate disk anular or segmented; flowers on both sexes 5 or 6-merous on the same plant..................
Studies on the Orchidaceae family in the Chapada dos Veadeiros National Park revealed a new occur... more Studies on the Orchidaceae family in the Chapada dos Veadeiros National Park revealed a new occurrence for the family to the flora of the Goiás state. Bulbophyllum adiamantinum, hitherto considered endemic to the state of Minas Gerais, is described here, illustrated, commented on its distribution, morphological relationships and period of flowering and fruiting. In addition, a map with distribution this species, its preliminary conservation status, images and notes on the anatomy of its vegetative system and its more morphologically, B. insectiferum, with which it can be confused, are provided. Anatomically, both species differ mainly by the presence or absence of silica bodies in the vegetative system and tracheoid idioblasts in the mesophyll, by the arrangement of the fibers and the appearance of the lumen of the cells of the exoderm, endoderm, pericycle and medulla in the roots. The characters that showed themselves to be variables were the number of vascular bundles, the shape o...
Phytotaxa, 2022
A new species from the state of Goiás, Brazil, Phyllanthus pterocaulis, is described and illustra... more A new species from the state of Goiás, Brazil, Phyllanthus pterocaulis, is described and illustrated, with comments on its geographic distribution and environmental preferences, phenology, morphological relationships, and systematic position. It is morphologically allied with Phyllanthus avicularis, P. heliotropus, and P. hyssopifolioides, but differs from all of them by a set of characters related to cymules sex, presence and types of trichomes on leaves and stems, leaf consistency, numbers of sepals in flower of both sexes, integrity of stamens, capsules and seeds. Additionally, we provide images of the new species in the field, conservation status, mapped distribution, the anatomical description of its stem and leaves, and a key to differentiate it from the other similar species belonging to Phyllanthus sect. Loxopodium occurring in Brazil. The new species is one of the few in the genus that occurs in shaded environments in seasonal dry forests within the Cerrado biome.
Iheringia, Série Botânica, 2021
RESUMO-Encyclia Hook compreende 150 espécies distribuídas em vegetações florestadas e savânicas d... more RESUMO-Encyclia Hook compreende 150 espécies distribuídas em vegetações florestadas e savânicas das Américas. Suas espécies apresentam anatomia dos órgãos vegetativos diversificada e útil taxonomicamente. Objetivou-se a descrição morfoanatômica dos órgãos do sistema vegetativo de Encyclia chapadensis L. C. Menezes, E. linearifolioides (Kraenzl.) Hoehne e E. osmantha (Barb. Rodr.) Schltr., visando levantar caracteres que as subsidiem em termos taxonômicos e que reflitam as condições ambientais. Algumas características dos órgãos estudados refletem adaptações à restrição hídrica (folhas suculentas e hipoestomáticas com hipoderme, raízes com velame expressivo e diferenciado em endo e epivelame, células armazenadoras de água e cutícula espessa), sustentação e suporte mecânico (fibras extravasculares e associadas aos feixes vasculares, espessamento em "fi" no córtex radicular), indicando que alguns caracteres anatômicos refletem as condições abióticas do ambiente impostas ao seu modo de vida. Os taxa podem ser diferenciados por caracteres foliares, caulinares e radiculares.
Check List, Jan 10, 2020
Botanical studies and exploration of Orchidaceae in Chapada dos Veadeiros National Park, Goiás st... more Botanical studies and exploration of Orchidaceae in Chapada dos Veadeiros National Park, Goiás state, Brazil, found a unreported species in the state. The presence of Scaphyglottis livida (Lindl.) Schltr. is reported, an illustration and distribution map are provided, and the morphological relationships of S. livida to other similar species, as well as its phenology, are discussed. A key to the species of the genus Scaphyglottis occurring in the Central-West Region of Brazil; images of these species are also provided.
Hoehnea, 2019
RESUMO Bulbophyllum é um dos maiores gêneros de Angiospermas, com 2.200 espécies em todo o mundo.... more RESUMO Bulbophyllum é um dos maiores gêneros de Angiospermas, com 2.200 espécies em todo o mundo. No Brasil ocorrem 60 espécies, das quais 10 são registradas para o estado de Goiás. Diante da carência de estudos taxonômicos sobre este gênero no Domínio Fitogeográfico do Cerrado (DFC), objetivou-se estudá-lo no Parque Nacional da Chapada dos Veadeiros, uma das áreas relictuais mais preservadas do DFC no Brasil. Foram registradas seis espécies: B. adiamantinum, B. ciluliae, B. epiphytum, B. exaltatum, B. plumosum e B. rupicolum. Bulbophyllum adiamantinum representa um novo registro para o estado de Goiás. As espécies seguem descritas e ilustradas em seus caracteres diagnósticos e que permitem o reconhecimento das mesmas. Comentários quanto a distribuição, preferências ambientais, relações morfológicas e fenologia são fornecidos, bem como uma chave dicotômica para identificação específica.
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Papers by Igor Soares dos Santos