Saturday, September 12, 2009

A lesson from my plants

Here are three plants from my collection:

Plant number 1














Plant number 2



















and finally...

Plant number 3















Which are cacti?

A little more information. At least one is a cactus.

The first plant grows in warm semi arid regions in South America. Some members of this group of plants get to be mid sized trees but most are shrubby.

The second plant has reduced leaves that function as thorns and it is found in deserts in the SW United States and Mexico.

The third plant lives in the jungles of Southern Mexico and into Central America.

All three plants have very similar looking and distinctive complex flowers, all organized in the same basic way.

So which are cacti? How do you know?

2 comments:

Rebecca Clayton said...

I recognize plant 2 & plant 3, and, if my memory of their blossoms is right, they are cacti. The cactus family has really unique flowers, and if you see the plant bloom, you know for sure if you've got a cactus.

Otherwise, you're out of luck, as the family has all sorts of different growth habits. That first plant reminds me of some Rubiaceae I've seen, but I suspect you've thrown it in here because it's a non-fleshy, unspiny cactus.

Quite a few fleshy members of the Liliaceae and Euphorbiaceae are commonly called "cacti" by florists and big-box stores that have a houseplant aisle.

My Stapelia is in lush bloom, if you can call it that. The caliphorids are humming all around the porch. The neighbor that gave me a start called it a "cactus." I had it for years before it bloomed, and until then, I thought it was some tropical spurge.

So when will you end our suspense?

Paul D. said...

Hi Rebecca,

OK, no more suspense...

All three are cacti (or is it cactuses)

The first plant is in the genus Pereskia.

http://en.wikipedia.org/wiki/Pereskia
The second plant I believe is an Echinocactus.

And the 3rd plant is an epiphyllum that I got from fellow blogger Ron Hudson.

I like Stapelids. They are in the Milkweed family like Hoya.