Raceme
A once-branched inflorescence that flowers from the bottom up (See also Panicle).
Rachis
The main axis of a compound leaf or inflorescence.
Radial
Parts arranged around a common center point.
Recurved
Bent or curved backward.
Reflexed
Bent abruptly backwards or downwards.
Resinous
Having or containing resin; being sticky.
Reticulate
Appearing like a net, or network (See also Net-veined).
Revolute
Margins rolled downward towards underside of leaf.
Rhizome
An underground stem, distinguishable by the presence of nodes, buds, or leaves (See also Stolon and Tiller).
Rhombic
Diamond-shaped with 4 sides; petiole attached at one of the corners.
Rosette
Radiating cluster of leaves.
Rounded
Wide curved shape that is wider than Obtuse with less of a point, while not being so flattened as to approach Truncate.
Rugose
A wrinkled surface as on a leaf.