Plant Profile: Dasylirion longissimum

Latin name: Dasylirion longissimum ("daz-ee-LEER-ee-on lon-JISS-ee-mum")
Common name: Mexican Grass Tree, Longleaf Sotol
Originally from: The Chihuahuan desert of northeastern Mexico
Blooms: A light yellow stalk of flowers grows 8-10' above the plant in summer.
Light: Full sun.
Water: No watering, just rain - don't let them get soggy or they will rot!
Height x width: 6-12' tall x 6-8' wide
Zones: 8b to 10b
Where to find in P. Garden: We have one up at the top of PG, and a clump of three small ones at PRG

You may have noticed our big new plant at the top of PG recently, and I blogged about how we got it from Craigslist and planted it too, which was a huge job. Why all the fuss? Well, for one it was hard work for the team and that deserves a mention, but it was worth it because this plant is unusual, and usually very expensive to get in a large size.

Long included in the Agave family (Agavaceae) this genus is now considered to be in the Nolinaceae family with Nolina and Beaucarnea. We have another in the same genus - D. wheeleri - in the garden too.

The name for the genus Dasylirion comes from the Greek words 'dasys', which means "dense" , "rough" or "shaggy" and 'lirion' meaning "lily" because of the long, rough leaves. However, D. longissimum doesn't have rough leaves. They're amazing - blue-green in color, 4-6' long, fairly stiff but not rigid, and smooth, with a point at the end. They radiate out from the core symmetrically, and the effect is like a giant koosh ball or a fiber optic lamp.

Show off that trunk!

Eventually (over decades) the plant will grow a woody trunk and the whole thing can get to 12' tall. In order to show off the trunk (and make it look longer) older, bottom leaves can be trimmed off to expose the trunk. Lots of ones for sale are trimmed so hard that no leaves are left on with an angle of less than about 60 degrees. It looks pretty unnatural but the plant appears older so probably commands more money.

The name for this plant in reference books has gone back and forth between Dasylirion longissimum and D. quadrangulatum. The reference books say D. longissimum is right, but other sources say it should be D. quadrangulatum. Either way, the name is as long as the leaves on this amazing plant!

We have a Dasylirion longissimum at PRG too, but this one was a much smaller plant when it arrived. Then it suffered damage by being crushed by someone, and I thought it would die. Nope, it grew back with multiple heads. It looks very scruffy, but perhaps one day it will recover fully and be as outstanding as the one at PG.