Answer: Dasylirion longissima (D. quadrangulatum) is also called the Mexican Grss Tree. The green leaves grow in a fountainlike clump, reaching about 5 feet high and wide. It is native to the deserts and mountains of the Southwest and Mexico and produces clumps of narrow, grassy leaves which spring from a woody base that can, with age, grow into a treelike trunk. It needs good drainage and is very drought tolerant. it should be a perennial in your southern California garden.
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