Have you ever wondered why some plants have thick, fat leaves and some have leaves that are long and thin? It turns out that scientists have asked that very question and they’ve come up with a reason for long and narrow leaves. One of the more obvious plants with long, thin leaves is the conifer, whose leaves are called needles. What other plant leaves are narrow and what purpose do skinny leaves on plants have? Let’s find out.
Purpose of Skinny Leaves on Plants
When scientists began to examine plants with long, thin leaves (Fun fact: Approximately 7,670 types of plants with long and narrow leaves exist), they discovered some commonalities. Plants near the equator tended to have larger leaves, but as you move toward the poles and into deserts, you see more leaves that are long and thin.
Why would plants with long, thin leaves abound in arid and northern regions? It seems that skinny leaves on plants have something to do with overheating and drying, but it also has to do with changes between hot days and frigid nights. Eventually, scientists determined that leaves that are long and thin are nature’s way of protecting plants from not only the risk of overheating and drying but also from freezing at night.
That makes sense for terrestrial plants, but what about aquatic plants? Reed and grass plants with long and narrow leaves have evolved for a reason as well. In the case of underwater plants, skinny leaves on plants take advantage of their length and light weight.
Aquatic plants are often long and thin so they can stretch upward towards sunlight and photosynthesize. Their light weight also means that they can easily mimic water currents, allowing them to go with the flow without risk of damage. The thin leaves allow water to flow through and around the plants, minimizing damage.
What Leaves are Narrow?
As mentioned, conifer leaves are narrow. Some conifers have needles, and some have scale-like leaves. Conifers such as pine trees, spruce, and firs have needles. The upside to needles on conifers is that the tree can keep its foliage year round so it can photosynthesize; the downside is that the tiny needles reduce the amount of photosynthesis.
There are many flowering perennial plants with long, thin leaves such as daylilies and the African iris. Flowering bulbs like daffodil, gladiolus, and tulip are all plants with skinny leaves. The thin leaves on these bulb plants help to create less drag and to elevate the comparatively heavy bloom.
Houseplants such as the spider plant, dracaena, ponytail palm, and snake plant have leaves that are long and thin as well. There are even succulents with long, thin foliage, although it tends to be fleshy. These include aloe vera and yucca.
It is rare to find a vine with long, thin leaves, but the cypress vine fits the bill with its needle-like foliage. There are even some shrubs that sport skinny foliage, such as the compact Oregon grape holly and the Emerald Wave sweet bay.