The reproductive success of flowering plants depends on pollination and seed dispersal. Due to their immobility, many flowering plants have evolved unique floral features to attract pollinators. A feature presumably related to pollinator attraction is the androgynophore; a stalk-like structure that supports and elevates the  reproductive organs of the flower. The androgynophore is present in several species, including crop plants Passiflora edulis (passion fruit) and Gynandropsis
gynandra (spider flower). A study of the androgynophores present in four Passiflora species suggested that pollinator-triggered movement of this feature aids in cross-pollination. Despite its likely connection to pollination biology, genes responsible for androgynophore development have not yet been characterized. We are using a combination of transcriptomic and histological methods and scanning electron microscopy to investigate the genetic basis and development of the androgynophore in G. gynandra. Not only will this research provide insight on gene function, it will also contribute to our understanding of diversification including the mechanisms behind elongation and fusion of floral features.

Floral fragrances mediate plant-pollinator interactions by attracting pollinators to floral resources such as pollen and nectar or enticing pollinators through deception by mimicking rewards, mates, and oviposition sites. Flowers can present limitless possibilities of fragrance blends that can be learned and recognized by pollinators. While some volatile compounds are nearly ubiquitous in floral scent profiles, other compounds are unique to certain plants. Thus, there may be general trends linking floral scent to pollinator class. Pollination studies on Gynandropsis gynandra (spider flower) provide conflicting evidence as to the insects responsible for pollination (hawk moth in Africa versus bee and butterfly in Asia). We are using the dynamic headspace technique and gas chromatography-mass spectrometry to collect and analyze the floral volatiles of G. gynandra from African and Asian populations. Description of these floral scent profiles will reveal the chemical similarities and differences and possible pollination syndromes of the two distributions.

Floral coloration is determined by the synthesis and accumulation of secondary metabolites. Carotenoids and flavonoids, in particular anthocyanins, are among the most common pigments found in petals. Variation of these pigments leads to a diversity of petal coloration acting as visual signals for attracting differing suites of pollinators. Pollinators can respond to petal color and patterns prior to approaching a flower. For example, petal patterns such as spots and stripes act as nectar guides to orient the pollinator to floral rewards. Cleomaceae is an ideal family to explore the basis of such features because it exhibits a vast amount of floral diversity. In this family, petal morphology and color can differ between species as well as within a flower of a single species. We are combining transcriptomic methods with high performance liquid chromatography to examine the basis and patterns of petal pigmentation between Cleomaceae species and within flowers to provide insight into the diversification and evolution of petal color.