Key to the species of Cyne

1Leaves completely sessile
1'Leaves obscurely to distinctly petiolate
2Leaves of each pair united at the margins into a cup
2'Leaves of each pair not united at the margins
3Inflorescence a sessile head of usually 3 sessile pairs of triads
3'Inflorescence a contracted raceme with an axis 1-4 mm long and usually 1 or 2 pairs of triads
4Young internodes quadrangular; leaves shortly acuminate at the apex
4'Young internodes terete; leaves obtuse or rounded at the apex
5Inflorescence axis 3-4 mm long; triads pedunculate; lateral flowers shortly pedicellate
5'Inflorescence axis c. 1 mm long; triads and lateral flowers sessile