Inflorescence shape

Determine shape of the inflorescence.

This powerful Feature is best determined when flowers are at anthesis or in mature bud.

Anthesis: when the flowers are fully expanded, i.e. stamens exserted.

On fruiting specimens the inflorescence shape can often be inferred from inspecting the disposition of flower scars on the receptacle, but be careful:

• taxa with globular heads commonly have obloid receptacles (select both Globular and Obloid/ellipsoid if in doubt);
• in taxa with cylindrical spikes the receptacle above the uppermost pod commonly withers and the receptacle therefore appears artificially shortened (thus, for shortly elongated receptacles it is prudent to select both Cylindrical and Obloid/ellipsoid).

Receptacle: the terminal region of the peduncle upon which the flowers are inserted.

Cylindrical. Flowers aggregated into elongated spikes.

Sometimes it is difficult to decide if heads are Cylindrical or Obloid/ellipsoid: if in doubt select both States.