Mechanism of nectar advertising in Genus Cyphia

Cyphia sp. [Locality: Sutherland]

Defined contrast between nectar guides and corolla base colour
Inflated corolla tube base
Wide C/tube mouth
Nectar guides composed of irregular horizontal dashes of varying width, becoming dark to feintly graduating, broad blotches in ascending lateral order
Inconsistent, low availability of flowers (highly season-dependant)

Cyphia volubilis [Locality: Cape Peninsula]

Starkly defined contrast between nectar guides and corolla base colour
Corolla tube base feintly abstended
Narrow C/tube mouth
Nectar guides composed of sketchy, irregular dots to lines, becoming dark and substantiated blotches (thin) in ascending lateral order. Noticeably compressed toward inner c/tube mouth
Low flower availability on individual plants but moderate relative density in locally common colonies (mildly season-dependant)

Cyphia bulbosa [Locality: Cape Peninsula]

Blended, moderately gradating contrast between UV-reflective nectar guides and corolla base colour
Corolla tube base slightly inflated
Moderate vertical gap in C/tube mouth, but compressed horizontally by basal margins of lower petal lobes
Nectar guides very feint and difficult to make out, likely accumulations of UV responsive chromatophores in petal subdermis. Flaring near C/tube mouth
High flower density on individual plants in dispersed but locally concentrated populations

Inferences

Negative corellation between nectar guide & base colour contrast, and gap of tube mouth in mm's (Higher contrast flowers having narrower mouths)
Weakly positive to inter-factor dependant corellation between nectar guide contrast and inflation of tube base (Lesser contrast equates to lesser inflation WHEN inter-specimen floral density in upwards flux) [probably related to equilibrium in by-product disposal through biosynthesis pathways]

Conclusions

Nectar guide contrast probably indicative of dilution of available nectar solution, with higher contrasts indicating very concentrated nectar (Family selective pollination syndrome)
Narrower line/ dot sketches, relative to width of substantiated blotch above, probably indicative of relative nectar abundance and propensity for gland refills for revisits (a controlling factor for local population dynamics of ideal pollinator)
Differences in Nectar guide contrast (particularly contrast between blotches and petal base colour) and patterning width/ symmetry likely indicative of species differentiation

Posted on October 5, 2021 10:37 AM by anthonywalton