Original video: https://youtu.be/viDhomp6W1I
Delivered on: 31 OCTOBER 2022
In general, the habit of a stem is erect or ascending, but it may lie prostrate on the ground, as in the sweet potato and strawberry.
A stem may climb on rocks or plants by means of rootlets, as in ivy; other vines have twining stems that twist around a supporting plant in a spiral manner, as in the honeysuckle and hop.
In other cases, climbing plants are supported by tendrils that may be specialized stems, as in the grape and passion-flower. In tropical climates, twining plants often form thick woody stems and are called lianas, while in temperate regions they are generally herbaceous vines.
A stolon is a stem that curves toward the ground and, on reaching a moist spot, takes root and forms an upright stem and ultimately a separate plant.
Among the subterranean stems are the rhizome, corm, and tuber. In some plants the stem does not elongate during its early development but instead forms a short conical structure from which a crown of leaves arises.
These may form a bulb (as in the onion and lily), a head (cabbage, lettuce), or a rosette (dandelion, plantain).
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