cordiform

It has large, alternating, cordiform leaves that have a long petiole and are pubescent on the underside.

The maps Donne would have been familiar with are not the Mercator-style maps, but instead cordiform maps, which appear in the shape of a heart.

More than simply heart-shaped, cordiform maps also allow the display of multiple worlds, with opposing hemispheres - and Sharp argues that Donne's work references such a multiple world map in lines 11 to 18.

In particular, she argues that Sharp's conclusions are incorrect, and that the actual words of the poem refer to a cordiform map showing a single world rather than one showing two worlds; "my face on thine eye", for example, not "eyes".

Despite these similarities, the species can be recognized by its ovate-elliptic to cordiform leaf shape and more membranaceous leaf texture than the other species in the section, and stem, inflorescence axes, and calyx vestiture mainly composed of glandular hairs.

The essential distinction is thus that, while both interpret Donne's work as referencing cordiform maps, Sharp sees it as referencing a map showing two worlds, while Walker maintains that the reference is to a map showing only one.