Cactus spines are modified 1) LEAVES. Numerous plants have spines of course, but in cacti, spines occur in clusters in the axil of leaves, even though the leaves are usually microscopic. honeylocust. Leaves modified for Reproduction: Typically, leaves are determinately growthed. Cactus Spines Are Modified Leaves. Leaves are modified into spines : Opuntia Stem has sharp thorns : _______ above-ground roots arising from the stem that can grow through the air and extend down into the soil ~provide extra absorptive capacity and anchorage/stability for the plant ... What kind of modified stem are thorns? Cactus spines are actually heavily modified leaves, although they don’t have any of the same structures that are found in normal leaves and are completely inert. Why leaves of desert plants are modified into thorns? 4.25) the minute leaves of the axillary bud are modified into spines. 6. Soft, broad leaves might be good at photosynthesis, but they lose a lot of water due to evaporation. Thus, in prickly pear (Opuntia; fig. The spine primordia is produced at the base of the axillary bud's shoot apical meristem; the … Thus, spines lose less water and … These new leaves were good at two things: avoiding water loss and protecting the plant (On this topic, I wrote a post on why cacti adapted to have spines instead of leaves). The grow, function and then die without sustaining new growth. mechanical defense. Cactus spines occur in clusters in the axil of leaves. In deserts, that is something that plants should avoid, so that they can store water. Plants lose water through their leaves. Cactus spines are also known as modified bud scales, which also are modified leaves. Most cactus morphologists have concluded that cactus spines are either modified leaves or modified bud scales (the difference is inconsequential because bud scales themselves are modified leaves). Complete the given analogy. 2 ... Answer: Spines are modified leaves which have less surface area. Ma'am as in the class we have studied the venation of leaves so in cactus as you know that the leaves are modified into spines or thorns so for example i am explaing a child that the leaves having parallel venation will have fibrous roots and the leaves having reticulate - Science - Getting to Know Plants A group of spines is termed an areole. Thorns, Spines and Prickles Cactus spines Cactus spines are usually modified leaves or shoots located in the axil of a leaf. Cacti have adapted to the harsh conditions they live in by developing areoles instead of branches and spines instead of leaves. What is the function of thorns? Spines for Defence: The non-photosynthetic leaves of cacti have become modified for defence. Over time, cacti modified them into clusters of sharp spines or hairs. Main menu Back Next Back to vegetative parts main menu Back to stem and leaf modification menu The leaf-apex in date-palm, dagger plant (Yucca) etc., is so modified, while in plants like prickly or Mexican poppy (Argemone), Amercian aloe (Agave), Indian aloe (Aloe), etc., spines develop on the margin as well as at the apex. Tendrils: In peas the terminal leaflet of the leaf has become modified into a tendril for climbing. Those cactus plants that have modified leaves have them as thorns, spines, spikes, quills, prongs or bristles. Cactus leaves are modified, because they're characterized by smaller surface areas.