Flowers may be borne individually on a plant, in which case they are called solitary flowers, or they may be part of a group, an inflorescence. An inflorescence is a group of flowers without foliage leaves. They often contain bracts (modified leaves) that differ from foliage leaves in size, shape, colour, texture or other characteristics.
Common types of inflorescences are:
Ament = erect or lax, spike-like inflorescences with scaly bracts and unisexual flowers without petals.
Catkin = soft spike or raceme of small unisexual flowers, the inflorescence falling as a unit.
Corymb = broad inflorescence in which the lower pedicels are successively elongated, giving it a flat-topped appearance.
Cyme = broad, more or less flat-topped, with the main axis terminating in a single flower which opens before the lateral flowers.
Head = dense cluster of stalk-less flowers (capitulum).
Panicle = main axis is branched one or more times and may support spikes, racemes, or corymbs.
Raceme = single axis with flowers arranged along the axis on pedicels.
Scorpioid curve = cyme which appears to coil like a scorpion.
Spadix = thick, fleshy spike-like inflorescence with very small flowers which are massed together and usually (partly) enclosed in a spathe.
Spike = single axis with flowers without pedicels arranged along the axis.
Umbel = flowers on pedicels of approximately equal length arising from the top of a peduncle.
Verticil = flowers arranged in whorls.
A raceme, spike, corymb, panicle, spadix, ament and catkin are all examples of indeterminate inflorescences in which the apical bud continues to grow for an indefinite period, sometimes as long as conditions remain favourable. In determinate inflorescences, such as cymes and scorpioid curves, the terminal bud becomes a flower (located at the end of the stem or in the centre of the inflorescence), and as such blocks further elongation of the stem. The terms determinate and indeterminate are not generally applied to heads and umbels because they have no obvious central axis.