My work on the Learn2grow plant database www.learn2grow.com/plants/ is like going on mini-vacations around the world as I research and write up some really great plants.  Right now I'm eyeballs-deep in the cactus family, and in particular the notorious cholla.  There are many species native to our southwestern deserts, but one is are real standout for its beauty and location.

In Joshua Tree National Forest, these wild Teddy-bear cholla grow only at a certain elevation at a place known as Cholla Gardens.  This is Cylindropuntia bigelovii, and it's likely that every plant you see in the picture above are all genetically identical clones.  The reason is that rainfall is sparse that it's rarely moist enough for seed to germinate.  So these plants have devised their own vegetative means of increasing their numbers.

Note the many weak jointed short segments that make up this mature old plant.  Cholla spreads vegetatively by "jumping" onto passers-by that chance to brush against its barbed spines, which catch and hold tenaciously.  Since these plants grow in cylindrical segments, a piece will detach with very little pressure allowing the human or animal to carry it further down the trail.  There it will eventually fall off, root and start a whole new genetically identical grove.

So little rain falls where many cholla live that they rarely, if ever grow from seed.  It would come from these fruits which the birds have hollowed out and will carry the seed far and wide.  Below is an example of the beautiful wood of the cholla that reflects its lattice-like skeleton showing the openings where areoles produce spines.  Fat cholla wood like this which is at least two inches in diameter is coveted for desert gardens and decor.  This is one of the most wonderful things about contributing to such a first class plant database - I get to wallow in the plants I love and discover so many new ones I can't wait to try!