ABSTRACT Ginger (Zingiber spectabile) is cultivated worldwide as a floriculture and landscaping species. Studies on the biology and floral morphology of this species are important for its improvement; however, they are scarce. We investigated the reproductive biology and floral morphology of gingers grown in a germplasm bank. Floral development was monitored during the pre-anthesis and anthesis periods. Floral morphometry, pollen viability, stigmatic receptivity, volume and concentration of nectar sugar, and performance of possible pollinators were evaluated. Ginger flowers had a 24-h durability. Ginger torch is an allogamous species that exhibits floral hercogamy like other Zingiberaceae. Ginger flowers had a 12-h anthesis. During anthesis, floral structures related to reproduction such as the style, stigma, and anther crest continued to develop, increasing floral herkogamy. Pollen viability was above 70% and the stigma remained receptive throughout the anthesis period. Hummingbirds were the only pollinators recorded in the study area that were able to move the anther crest. Fruiting was determined in a natural pollination system. The occurrence of nocturnal anthesis characterized by an increase in the development of reproductive structures and nectar production suggests that the species is adapted to nocturnal visitors.

ABSTRACT Psychotria ipecacuanha, commonly known as Ipeca, is a medicinal plant of pharmacological and economic value. The species is distylous; it has populations with two floral morphs, one with long and one with short styles. Apart from the presence of two floral morphs in a balanced ratio (1:1), reciprocal herkogamy of the reproductive organs between alternative morphs is desirable to maintain cross-pollination. The risk factors for genetic erosion and conditions for sexual reproduction in natural populations of P. ipecacuanha were investigated. The main risks for genetic erosion in four populations studied were: habitat change in the forest fragment where they occurred and in the surrounding area over the last 20 years; proximity to agricultural areas; frequency of drought affecting the forest fragment; and the area occupied by the species within the forest fragment. All evaluated populations were isoplethic with the reciprocity of reproductive organs varying across populations. Anthropogenic factors, associated with morphological and reproductive characteristics (e.g., low reciprocity between anther and stigma and low pollen production), indicate risks for the maintenance and reproduction of Ipeca in the population of the municipality of Denise. Habitat loss, small clusters, and the low number of reproductive plants jeopardize the survival of the studied populations.

RESUMO A apresentação secundária de pólen consiste em um mecanismo floral onde a apresentação de pólen se dá em outras estruturas florais além da antera, a fim de aumentar a precisão da dispersão do pólen pelos vetores. Este estudo teve como objetivo descrever a dinâmica temporal da apresentação secundária de pólen e as características morfológicas e morfométricas nos estádios de pré-antese e antese, em genótipos oriundos de cinco populações naturais de H. psittacorum, na região centro-oeste do Brasil. Para o estudo das características da morfometria floral foram avaliados comprimento da flor, altura do estigma e da inserção do filamento do estame na pétala. A morfologia floral dos botões em pré-antese e das floresforam avaliadas quanto à presença ou ausência d características como hercogamia, forma da inserção do filamento do estame na pétala, região de pelos estilares e de deposição secundária de pólen. Tratamentos de polinizações controladas, tais como: autopolinização, geitonogamia, polinização cruzada e polinização natural e crescimento do tubo polínico foram realizados. A hercogamia floral e a transferência de pólen para os pelos aderidos na região estilar foram claramente observados durante a antese, constituindo o primeiro registro de ocorrência de apresentação secundária de pólen em Heliconiaceae. O crescimento do tubo polínico foi inibido na região estigmatica, estilete e base do pistilo. O posicionamento dos estames acima do estigma, a viabilidade do pólen e a receptividade do estigma durante a antese de flores de H. psittacorum podem favorecer a autopolinização. A presença de tricomas no estilete auxilia na retenção de grãos de pólen. A baixa taxa de frutificação em polinizações controladas e naturais sugere que a principal forma de propagação de H. psittacorum nas áreas de estudo é baseada na reprodução assexuada.

ABSTRACT The secondary presentation of pollen consists of a floral mechanism where the presentation of pollen occurs in other floral structures in addition to the anther, in order to increase the precision of the dispersion of the pollen by the vectors. This study aims to describe the temporal dynamics of secondary pollen presentation, and morphological and morphometric characteristics in stages of pre-anthesis and anthesis in genotypes of five natural Heliconia psittacorum populations. For the study of floral morphometry traits of length of the flower, stamen, stigma and height of filament insertion in the petal in bud and flower were measured. The floral morphology of pre-anthesis buds and flowers in anthesis, the presence or absence of characteristics such as herkogamy, region of filament insertion in the petal, region of stylar hairs, and of secondary pollen deposition were evaluated. Treatments of controlled pollinations, self-pollination, geitonogamy, cross-pollination, natural pollination and growth to pollen tube were sampled. Floral herkogamy and pollen transfer to the adhered hairs in the stylar region were clearly observed during anthesis, constituting the first record of occurrence of secondary pollen presentation in Heliconiaceae. Pollen tube growth was inhibited in the stigmatic, style and basal regions of the pistil. Natural fruiting produced little or no fruit. The positioning of the stamens above the stigma, pollen viability and stigma receptivity during anthesis of H. psittacorum flowers may favor self-pollination. The stylar hairs observed in all H. psittacorum populations' help in the retention of pollen grains. The low fruiting rate in controlled and natural pollinations suggest that the main propagation form of H. psittacorum in the study areas is based on asexual reproduction.

Resumo Este estudo teve por objetivos analisar a fenologia de floração, a biologia e a morfologia floral, o sistema e o sucesso reprodutivo dos morfos florais de Psychotria carthagenensis Jacq. O período de floração se estendeu de maio (estação seca) a janeiro (estação chuvosa). A floração dos morfos florais foi sincronizada e o número médio de inflorescências, de botões em pré-antese e de flores abertas por indivíduos foram semelhantes. A antese das flores de ambos os morfos foi de 12 horas. Houve diferença significativa no comprimento da corola, dos lobos estigmáticos, das anteras e altura do estilete entre os morfos florais. A viabilidade de pólen foi alta entre ambos os morfos. A formação de frutos ocorreu em polinizações intramorfos e intermorfos e não houve diferença significativa na produção de frutos e sementes em tratamentos intermorfos. Os atributos florais analisados sugerem que os dois morfos contribuem similarmente para a manutenção da espécie na área de estudo.

Abstract This study aims to examine flowering phenology, floral biology and morphology, and the reproductive system and success of the floral morphs of Psychotria carthagenensis Jacq. The long flowering period lasts from May (dry season) to January (rainy season). Flowering of the floral morphs was synchronized and the number of inflorescences, buds in pre-anthesis and flowers per plant were similar. Anthesis of the flowers of both morphs was 12 hours. Significant differences were observed in the corolla length, the stigmatic lobes, anthers and styles between floral morphs. Pollen viability was high in both morphs. Intermorph and intramorph pollinations resulted in fruit set. There was no significant difference between intermorph treatments in fruit and seed production. The flower attributes indicate that both morphs contribute similarly to species persistence in the study area.