Leaves vary as to texture, and may be—
coriaceous, or leathery;
succulent, or juicy;
scarious, or dry and thin;
fleshy, or thick;
herbaceous, or thin.
ARRANGEMENT
According to their arrangement on the stem, leaves are—
alternate, when distributed singly at different heights on the stem;
opposite, when two stand opposite each other at the nodes;
whorled, when more than two are borne at a node, equidistant in a circle around the stem.
INFLORESCENCE
Inflorescence is a term commonly applied to the mode of flowering—i.e. to the arrangement of blossoms on the stem and their relative positions to one another.
A peduncle is the stem of a solitary flower, or the main stem of a flower-cluster;
a scape is a peduncle growing from the ground;
a pedicel is the stem of each flower in a cluster;
a bract is a small floral leaf;
an involucre is a collection of bracts around a flower-cluster or around a single flower.
Flowers may be solitary or clustered.