Dalechampia margarethiae (Euphorbiaceae), a New Species from Southeastern Brazil

Abstract—A new species of Dalechampia from southeastern Brazil, belonging to Dalechampia sect. Dioscoreifoliae, is described and illustrated here. Dalechampia margarethiae is a twining vine occurring exclusively in Espírito Santo state. Its pseudanthia are similar to those of D. peckoltiana and D. pentaphylla, but D. margarethiae differs in a set of important characters, including having cylindrical, down-curved style tips, staminate flowers at anthesis having unreflexed sepals with stamens born on unelongated columns, whitish floral resin, and simple, entire, cordate leaves.

Coevolution with pollinating resin midges led to resin-filled nurseries in the androecia, gynoecia and tepals of Kadsura (Schisandraceae)

Background and Aims Resin is a defence against herbivores and a floral reward in a few African and South American species whose bee pollinators collect it for nest construction. Here we describe a new role for floral resin from the Asian genus Kadsura (Schisandraceae). Kadsura tepals tightly cover a globe formed by carpels (in females) or near-fused stamens with fleshy connectives (in male flowers of most, but not all species). Methods We carried out field observations at four sites in China and used pollinator behavioural assays, chemical analyses and time-calibrated insect and plant phylogenies to investigate the specificity of the interactions and their relationship to floral structure. Key Results Nocturnal resin midges (Resseliella, Cecidomyiidae) walk around on the flowers’ sexual organs to oviposit, thereby transferring pollen and wounding tissues. The larvae then develop in resin-filled chambers. Male and female floral scents are dominated by α-pinene, while the resinous exudate is dominated by caryophyllene. As revealed by barcoding of multiple midge larvae per flower species, the mutualisms are species specific and appear to have evolved over the past 6–9 million years. Conclusions Resin feeding, not pollen or ovule feeding, by midge larvae explains the abundant Kadsura exudates, highlighting the poorly known world of nocturnal flower–fly interactions.

Floral, resin-secreting trichomes in Maxillaria dichroma Rolfe (Orchidaceae: Maxillariinae)

Resin-secreting, sunken, glandular trichomes have been described from the vegetative organs of <i>Maxillaria</i> and certain related taxa. However, until now, these hairs have not been recorded for <i>Maxillaria</i> flowers, nor have they been examined at the ultrastructural level for any part of the plant. Here for the first time, these hairs are described using LM, SEM and TEM, and their possible functions discussed.

Floral Resin of Tovomitopsis saldanhae (Guttiferae) and 7-Epi-nemorosone: Structural Revision

The floral resin of Tovomitopsis saldanhae (Guttiferae) is composed of poliisoprenylated benzophenone and the major constituent is 7-epi-nemorosone which has now been revised.

Polyisoprenylated Benzophenones In Cuban Propolis; Biological Activity Of Nemorosone §

The Copey tree (Clusia rosea) has a large distribution in Cuba and its floral resin is a rich source of polyisoprenylated benzophenones. To determine the presence of these natural products, we carried out a study by HPLC of 21 propolis samples produced by honey bees (Apis mellifera) from different provinces of Cuba. Nemorosone resulted to be the most abundant polyisoprenylated benzophenone and the mixture of xanthochymol and guttiferone E was also observed, but in minor proportion. We studied the biological activity of the pure natural product nemorosone and its methyl derivatives. We found that nemorosone has cytotoxic activity against epitheloid carcinoma (HeLa), epidermoid carcinoma (Hep-2), prostate cancer (PC-3) and central nervous system cancer (U251). It also exhibited antioxidant capacity. Methylated nemorosone exhibited less biological activity than the natural product

Resin-collecting bees (Apidae) on Clusia palmicida (Clusiaceae) in a riparian forest in Brazil

Primary flower resources to bees, i.e. those that satisfy basic needs, such as feeding and reproduction (Faegri & van der Pijl 1979), include pollen, nectar, oil, resin and gums. Resins are used in nest construction as a waterproof and structural material (Simpson & Neff 1981). It is also excellent antimicrobial compound, and a sticky defence against ant attacks (Armbruster 1984, Dressler 1982, Lokvam & Braddock 1999, Michener 1990, Roubik 1989, Sakagami et al. 1989). Plant species with flowers which produce terpenoid resins are rare (Armbruster & Webster 1979). Clusia L. (Clusiaceae), Clusiella Planch. & Triana (Clusiaceae), and Dalechampia L. (Euphorbiaceae) are the only known plants that secrete resins from floral structures (Armbruster 1984, Armbruster & Webster 1979, Bittrich & Amaral 1996). Although resin-producing plants provide an essential resource for a large number of bees in tropical communities, there are few studies about resin-collecting bees on Clusia spp. Skutch (1971) was the first to report visits on Clusia by stingless bees to collect floral resin. Other reports include observations on C. odorata Seem. (Croat 1978, Ramirez & Gomez 1978), C. alata Pl. & Tr. (Ramirez & Gomez 1978), and C. nemorosa G. F. W. Meyer (Armbruster 1984, Bittrich & Amaral 1996, Lopes & Machado 1998, Mesquita & Fransciscon 1995). Recently, Bittrich & Amaral (1996, 1997) have described the flower morphology and pollination biology of other Clusia species from Central America and Venezuela.