What is a bulb?

Lee Poulsen wpoulsen@pacbell.net
Mon, 07 May 2012 21:33:12 PDT
I personally love the 4 item key that PBS developed that Mary Sue referenced. It accords extremely well with my purely non-technical, but avidly hobbyist idea of what I seek to grow in my "bulb" collection", especially items 2 and 3. I've never grown Pleiones, but I have grown Bletilla and I first grew it from a package of Bletilla "bulbs" that I bought one year at the same time that I bought several packages of other "bulbs" at my local mainstream nursery long ago. They were all sold in the same section of the nursery and the sign labeled the section as "bulbs". I buried them all in pots fill with potting mix and they all started growing leaves and eventually bloomed, and thus was born my initial interest in "bulbs"! (Those other "bulbs" were cannas and Ismene, probably x festalis, but I didn't know that at the time.) As my collection (and my bulb lusts) grew, there were certain genera where I wanted to grow every species of them that I could get my hands on. Even after I discovered that some of the species actually didn't have a "bulb" I could plant in the soil, I still wanted it as a "bulb" because I wanted the "whole collection", so to speak. Then I learned that a lot of what I liked, and grouped in my mind and in my collection as "bulbs", all belonged to a small handful of families. So those entire families have become "bulb" families in my mind and in my collection--these families include the amaryllids and the irids for example, both of which I seem to like almost every genus and species included in them.

As this question has popped up again and again over the years, I've at times become concerned that some "bulbs" I really, really, like would have to be "demoted" from being "bulbs" in my mind, kind of like Pluto being kicked out of the planet club. So I have been very grateful to learn that quite a number of them are listed as having that catch-all feature called a rhizome, and thus could continue to be "bulbs" in my collection! I love when the wiki mentions this. It's one of my best mental defenses when someone disses one of my favorite "bulbs" as not being enough of a geophyte to even loosely consider it a "bulb". (For example, kangaroo paws, especially the black one, Macropidia fuliginosa, which along with Anigozanthos are both listed as "growing from a rhizome".) I don't know that I've ever seen a Xanthorrhoea, so I can't say if it would hit me as being in the "bulb" family. But I did get to see a Doryanthes in bloom on one occasion, and even though it was gigantic, the "bulb"-lust part of my brain really wants to get and try growing one one of these days--when I can find enough room to plant one somewhere... Another example that just screams "bulb" at me is Xeronema callistemon; luckily it is also listed as "growing from a rhizome". Yay!

So I love the fact that PBS has decided to include bulbs, bulb-like geophytes, honorary "bulbs", and even orchids such as Bletilla, which will always be a "bulb" to me. Oh, and I just looked up Doryanthes which is listed as having both a rhizome _and_ forming evergreen bulbs around the mother plant. Yay again!

--Lee Poulsen
Pasadena, California, USA - USDA Zone 10a
Latitude 34°N, Altitude 1150 ft/350 m

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