Rare bulbs may be wrapped singly in tissue paper for storing.
In high quality tobaccos the leaves are " primed " or picked singly as they ripen, but in the great bulk of American tobaccos the whole plant is cut close to the ground when the middle leaves are about ripe.
The male sexual cells are produced singly in the terminal cells of branches.
The firs are distinguished from the pines and larches by having their needle-like leaves placed singly on the shoots, instead of growing in clusters from a sheath on a dwarf branch.
The tentacles may be scattered singly round the margin of the umbrella (" monerenematous ") or arranged in tufts (" lophonematous "); in form they may be simple or branched (Cladonemid type); in structure they may be hollow (" coelomerinthous "); or solid (" pycnomerinthous ").