AY Honors/Cacti/Answer Key

1. Name the chief characteristics of a cactus.

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 three uses of cacti.

Cacti are used for:

1. Decorating - as houseplants, in dry gardens, or, even as a fence.

2. Edible Fruit Producing - such as Prickly Pear, Hylocereus, Dragon fruit.

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?

Cacti are mostly found in extremely arid and hot environments.

The majority of cacti are found in the North and South America as well as in the West Indies.

Why? Cacti are adapted to arid and hot environments.

4. Know and identify from life or pictures 15 species of cacti.

Hey! This is your part. Enjoy!

I took photos of these two. Can you identify them?

File:Cacti70512c.png

Cacti

File:Cacti70315a-davismtns.png

Davis Mountains

Now go and identify more...

• Cactaceae-compass barrel.jpg
• Cactaceae-cows tongue.jpg
• Cactaceae-golden barrel.jpg
• Cactaceae-mission cactus.jpg
• Cactaceae-mojave prickly pear.jpg
• Cactaceae-old man of the andes.jpg
• Cactaceae-old man of the mountains.jpg
• Cactaceae-purple pancake cactus.jpg
• Cactaceae-rabbit ears-with-rabbit.jpg
• Cactaceae-red barrel cactus.jpg
• Cactaceae-silver cholla.jpg
• Cactaceae-star cactus.jpg
• Cactaceae-teddy bear cholla.jpg
• Cactaceae-south american.jpg

5. Photograph, observe or sketch at least 10 species of cacti and classify them or grow at least 3 different species of cacti.

There are different tribes of cacti:

• Azureocereus imperator 3.jpg

  B. hertlingiana (Tribe Browningia)

• Ariocarpa retusus 1.jpg

  Ariocarpus retusus (Tribe Cacteae)

• Carnegiea gigantea top.jpg

  Calymmanthium (Tribe Calymmantheae)

• Cereus-peruvians1.jpg

  Cereus peruvianus (Tribe Cereeae)

• Hylocereus undatus.jpg

  Hylocereus undatus (Tribe Hylocereeae)

• Parodia magnifica1.jpg

  Parodia magnifica (Tribe Notocacteae)

• Bergerocactus emoryi1MIBEA.jpg

  Golden cereus (Tribe Pachycereeae)

• Schlumbergera gaertneri.JPG

  Schlumbergera gaertneri (Tribe Rhipsalideae)

• Denmoza rhodacantha 1.jpg

  D. rhodacantha (Tribe Trichocereeae)

• Austrocylindropuntia subulata0.jpg

  A. subulata (Tribe Austrocylindropuntieae)

• Opuntia brasiliensis2.jpg

  Cuija (Tribe Opuntieae)

• Pterocactus kuntzei.jpg

  Pterocactus tuberosus (Tribe Pterocacteae)

• Puna subterranea.jpg

  Maihueniopsis subterranea (Tribe Tephrocacteae)