Different types of stems: axis of a plant.
HERBACEOUS STEMS: They do not have developed ligneous stiffened structures. They are
generally frail. We find them in plants like the following:
Annual plants: Plants with a year life-time. Weeds generally belong to this group.
Vivacious plants:Plants with aerial stems lastinga single season, but keeping underground structures from which new stems spring again next season.
LIGNEOUS STEMS: They have developed rigid, stiffened structures, what we normally know as “wood” . According to the height they attain we classify them into:
Trees: Plants with ligneous stems, with a superior height of five meters. In this case we call
the stems trunks. They do not generally branch up to a considerable distance from the soil.
Shrubs:Are those plants with ligneous stems, from one to five meters tall. In this case,
Bushes : Ligneous plants shorter than one meter tall.