Table 2.

Characteristics of trichomes and nectaries in O. picridis flowers

Colour of glandular trichome heads	White-yellow
Colour of glandular trichome secretion	Light yellow
Trichomes on sepals	Glandular, capitate, dense, on the abaxial surface Glandular, conoidal, rare, on margins
Trichomes on petals	Glandular, capitate, dense, on the abaxial surface
Trichomes on stamens	Non-glandular, in the bottom part of filaments, ca. 2/3 of the length Non-glandular, on anther sutures
Trichomes on the pistil	Glandular, capitate, in the upper part of ovary and style under stigma
Location of the nectary	At the base of the ovary (gynoecial nectary)
Colour of the nectary	Yellow-orange
Type of nectar exuded	Nectarostomata
Vascularisation of nectary	None
Starch grains in nectary parenchyma	Present, numerous
Nectar transport	Via symplastic and apoplastic routes