What is the structure of cactus?
What is the structure of cactus?
Cacti generally have thick herbaceous or woody chlorophyll-containing stems. Cacti can be distinguished from other succulent plants by the presence of areoles, small cushionlike structures with trichomes (plant hairs) and, in almost all species, spines or barbed bristles (glochids).
What is protective structure of plants?
A protective structure is defined as any structure designed to modify the environment in which plants are grown. Protective structures, such as greenhouses, screen houses, and tunnels, are known worldwide as production systems for high-quality vegetable and fruit crops.
What special structure does a cactus have?
Cactus spines are produced from specialized structures called areoles, a kind of highly reduced branch. Areoles are an identifying feature of cacti. As well as spines, areoles give rise to flowers, which are usually tubular and multipetaled.
Why do cactus have prickles?
So, one reason for why cacti have needles is to prevent thirsty or hungry animals from eating or damaging the plant. These spine clusters almost act like mini-umbrellas that help to shade the plant. By shading the cactus, these spines also help prevent the cactus from losing water through evaporation.
How are the stems of a cactus protected?
Most species of cactus are well-protected by sharp bristles and spines, which serve to deter most herbivores. The stems of cactus plants have numerous cushion- or pit-like structures known as areoles on their surface, from which usually emerge clusters of spines.
What are the spines on a cactus plant?
The stems of cactus plants have numerous cushion- or pit-like structures known as areoles on their surface, from which usually emerge clusters of spines. In terms of developmental biology, areoles are usually interpreted as being incompletely developed, axillary stem branches. The spines are actually modified leaves.
What kind of tissue does a cactus have?
For example, spines may vary in length and color. Characteristics: Most cactus are stem succulents. They have fleshy stems. Most have very little woody tissue. They never have leaves. Cactus spines probably evolved from leaves.
What is the biology of a cacti plant?
Biology of cacti. Cacti are perennial plants. Their stems are fleshy or succulent, and are cylindrical or flattened in shape. The stems are green-colored, and are photosynthetic, usually performing this function instead of leaves, which are greatly reduced in abundance or even absent in most mature cacti.
Most species of cactus are well-protected by sharp bristles and spines, which serve to deter most herbivores. The stems of cactus plants have numerous cushion- or pit-like structures known as areoles on their surface, from which usually emerge clusters of spines.
The stems of cactus plants have numerous cushion- or pit-like structures known as areoles on their surface, from which usually emerge clusters of spines. In terms of developmental biology, areoles are usually interpreted as being incompletely developed, axillary stem branches. The spines are actually modified leaves.
What are the physical characteristics of a cacti?
Physical characteristics. Cacti generally have thick herbaceous or woody chlorophyll-containing stems. Cacti can be distinguished from other succulent plants by the presence of areoles, small cushionlike structures with trichomes (plant hairs) and, in almost all species, spines or barbed bristles (glochids).
How does a cacti protect itself from the Sun?
Spines not only defend the juicy stems of cacti against ravenous succulent-eaters, but also shade them from the relentless desert sun. (Cacti that grow in non-desert environs wear a lighter covering of spines.) The New Zealand tree nettle (Urtica ferox), showing secretory (glandular), or stinging, hairs (trichomes).