By: Wendy Langhans
My Uncle’s question caught me by surprise, “Hey, Wendy. Are all cactus succulents?”
We were in Phoenix, exploring the Desert Botanical Garden  with family. My uncle is a curious man, both by inclination and profession. A retired physics professor, he has spent many years asking questions and looking for answers.
A half-baked answer would not do. So I stopped and thought for a moment. “Yeah. I think so.” And then I smiled, because at that moment I knew what I would write about this week.
“All cacti are succulents, but not all succulents are cacti.” Or so says the Arizona Game & Fish Department . That’s the short answer. But answering one question often leads to asking another - what makes a plant a succulent?
The Arizona-Sonora Desert Museum website  describes succulents as plants with living tissue “that... serves and guarantees a ...temporary storage of utilizable water, which makes the plant... temporarily independent from external water supply...".
OK, that explains plants like Prickly Pear Cactus (various Opuntia species) that store water in their fleshy pads and Saguaro cactus (Carnegiea gigantea), which can soak up over 200 gallons of water after a rainstorm.
But what about plants like tulips and daffodils. Don’t their bulbs contain water? And what about potatoes? Don’t their tubers contain water? Aren’t they succulents too?
Well...yes...and no. Part of the problem, as I see it, is a fuzzy definition. Is the definition based on form - living tissue for water storage, fleshy stems and leaves, broad and shallow roots? Or function - CAM metabolism, growth during the dry season? Or use - gardeners plant succulents in an dry environment? The January 2011 edition of the Desert Breeze Newsletter  has an interesting article, “What is a Succulent Anyway?”, that describes the issue in greater detail.
But I’d like to propose a simple, non-technical analogy to describe a succulent. Assume that water is the plant equivalent of our roll of quarters. We save our quarters for a rainy day. Succulents save their quarters for a dry one.
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Trail Maintenance Schedule. Come join our volunteers as they help maintain our trails. Contact Steve at email@example.com  for time and place.
Wednesday mornings, January 4, 11, 18 & 25.
Saturday mornings, January 14 & 28.
Saturday, January 21, 8-10 AM. Flying into a New Year at Towsley Canyon. Birds love Southern California’s gentle winters as much as we do. Volunteer Naturalist Roger will show you Towsley’s birds from near and far. Beginners are welcome on this easy walk. Bring binoculars. Meet at Towsley Canyon’s front parking lot. For a map and directions, click here .
Sunday, January 22, 12:30-2:30 AM. Adaptations for Survival. Towsley Canyon. Join Volunteer Naturalist Wendy for an afternoon resolving winter’s dilemma. Discover their amazing adaptations to survive the chilly days. For a map and directions, click here .
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