Stems are the core to every plant. They have four main functions: support, transportation of fluids, storage of nutrients, and production of new living tissue. But not every plant stem is made the same. Different species of plants have different types of stems, ranging from soft and flexible to tough and rigid.
Herbaceous stems are only supported by the water running through the inside of the stem. If there is little water in the plant, the plant will fall over and bends towards the ground. Garden vegetables have herbaceous stems. Herbaceous are nonwoody and die at the end of the growing season. Some types of herbaceous include:
- Trailer – A weak stem that spreads over the surface of the ground without rooting at the nodes.
- Creeping Plant – A plant grows horizontally on the ground and gives off root at each node E.g. Grasses
- Climber – stems that cling or wrap around other plants or structures.
- Bulb – a short vertical underground stem with fleshy storage leaves attached, e.g. onion, daffodil, tulip.
- Tuber – a swollen, underground storage stem adapted for storage and reproduction, e.g. potato.
Herbaceous stems are thin, soft and green in color except those that grow underground, like potato and onion stems. Plants with herbaceous stems are also known as herbs. To make herbaceous plants stronger, it is important to feed them nutrient rich supplements like Complete Hydroponics nutrients.
Woody stems are taller, thicker and harder than herbaceous stems. When they are fully grown, a bark is produced.
Plants with woody stems may be categorized as trees or shrubs. A tree will usually have a thick main stem, known as a trunk. The branches start forming some distance above the ground. In a shrub, there are many thin stems, which have many branches. Here are some different growth patterns of a woody plant:
- Excurrent – The main axis shows continued growth and the lateral branches develop regularly giving a conical appearance to the tree E.g. Pine trees
- Deliquescent – The growth of lateral branch is more vigorous than that of the main axis. The tree has a rounded or spreading appearance E.g. Lemon tree
- Caudex – Its an unbranched, stout, Cylindrical stem, marked with scars of fallen leaves E.g. Coconut trees
- Culm – Erect stems with distinct nodes and internodes. stem shows jointed appearance E.g. Bamboo
Other Types Of Plant Stems
Acaulescent – used to describe stems in plants that appear to be stemless. Actually, these stems are just extremely short, the leaves appearing to rise directly out of the ground, e.g. some Viola species.
Caespitose – when stems grow in a tangled mass or clump or in low growing mats.
Cladode (including phylloclade) – a flattened stem that appears more-or-less leaf like and is specialized for photosynthesis, e.g. cactus pads.
Corm – a short enlarged underground, storage stem, e.g. taro, crocus, gladiolus.
- Lianas – A long woody perennial twiner
- Isotomous: Initial branches are of equal size/vigor and also diverge at similar angles from the main axis
- Anistomous: Initial branches may be of unequal size/vigor, but more commonly daughter branches diverge at different angles from the main axis. One branch at a slight divergence from the main. The other much more divergent, creating an “overtopped” appearance.
- Pseudomonopodial: Appearance is such that one branch continues the upright, perpendicular growth of the plant, while the other is much more divergent creating side branches.