Adventist Youth Honors Answer Book/Nature/Cacti
See also Cacti - Advanced
|Skill Level 1|
|Year of Introduction: 1944|
1. Name the chief characteristics of a cactus.[edit | edit source]
- Areoles - Flowers, branches, spines sprout from these- no other plant has this feature.
- Spines - Perhaps the most familiar feature of cacti, spines can vary greatly in appearance, shape, size, and color. Spines are not thorns.
- Flowers - Flowers are not unique to cacti, but cacti flowers are unique. Cacti flowers are typically quite spectacular and very complex. Unfortunately this field mark is only helpful, of course, if the plant happens to be blooming.
- Leaves - Most cacti do not have leaves, however, some do. Pay special attention to the presence or absence of leaves.
- Origin - All cacti are native to the America's and surrounding islands. With one exception - Rhipsalis baccifera. Although, world wide cultivation has made this less helpful for identification.
2. Name four uses of cacti.[edit | edit source]
- Cacti are used for:
- 3. Psychoactive uses - the Peyote, Lophophora williamsii, is a well-known psychoactive agent used by Native Americans in southwestern United States.
- 4. Host for bugs - the Opuntia is also used as a host for cochineal bugs for the Cochineal dye industry.
3. In what places are cacti the most plentiful? Why?[edit | edit source]
- Most cactus species, there are some 2500 of them altogether, are not really suited to live in a true desert. Then mainly occur around the Tropics of Cancer and Capricorn, 23 degrees N and S, these zones have the largest diversity. In Mexico alone, you can find several hundred species of cactus.
- But some indeed do live in the desert. In North America, the deserts are further north, about from the Tropic of Capricorn north to around 40 degrees N. The harshest conditions are found between 28 degrees N and 32 degrees N, approximately.
- WHY? Because they can, what makes them survive is their adaptation to the environment. When it rains, they take advantage of it and store as much water as they can. Their roots are on the surface, which enables them to collect the water and store it in the stems quickly. Note that if over watered root rot can accrue.
4. Know and identify from life or pictures 15 species of cacti.[edit | edit source]
Hey! This is your part. Enjoy!
I took a photo of this cactus. Can you identify it?
Now go and identify more...
5. Photograph, observe or sketch at least 10 species of cacti and classify them or grow at least 3 different species of cacti.[edit | edit source]
There are different tribes of cacti:
B. hertlingiana (Tribe Browningia)
Ariocarpus retusus (Tribe Cacteae)
Calymmanthium (Tribe Calymmantheae)
Cereus peruvianus (Tribe Cereeae)
Hylocereus undatus (Tribe Hylocereeae)
Parodia magnifica (Tribe Notocacteae)
Golden cereus (Tribe Pachycereeae)
Schlumbergera gaertneri (Tribe Rhipsalideae)
D. rhodacantha (Tribe Trichocereeae)
A. subulata (Tribe Austrocylindropuntieae)
Cuija (Tribe Opuntieae)
Pterocactus tuberosus (Tribe Pterocacteae)
Maihueniopsis subterranea (Tribe Tephrocacteae)