Toothless Spoon Yucca. Dasylirion longissimum, Sotol, Agave, Family, ( Agavaceae )Toothless Spoon Yucca: Also Called: Square-leaf Sotol, Mexican Grass Tree, Toothless Grass Tree, Toothless Sotol, Dasylirion quadrangulatum, Dasylirion longissima, Dasylirion longissimum var. treleasei. We wish to thank Wikipedia, the free encyclopedia for some of the information on this page. We share images and information with Wikipedia. Dasylirion longissimum is a shrub with an evergreen trunk that slowly develops up to 12 to 15 feet tall, each year. It's base is about 6 to 8 feet in diameter, with green leaves up to about 4 to 6 feet long and about 0.24 inch wide. It's flowers develop upon the top 1/3 to 1/4th part of the stalk. the flowers are tan to cream - white in color. It's flowers are attractive to bees, and if fertilized, they will produce a colorful red - pink plume of tightly packed seeds, where the flowers were earlier, in the fall. It can be planted in full sun to light shade. It is drought tolerant and said to be cold hardy to at least 15 � F. Quick Notes: Height: 4 - 6 feet tall. It spreads to about 6 feet. Flowers: A large stalk emerges from the center of the plant, it becomes 6 to 15 feet tall. Then dioecious; small, greenish white flowers clustered tightly on the stalk emerge from pink buds on the stalk; it bears female and male flowers on different plants; the female plant flower structure is more rounded, on the male plant it is more narrow. Flowering Time: Phoenix Arizona, March to April. Fruit: It has elliptic to ovate capsule fruits which are 7 mm long and 5 to 6 mm wide. They contain 1 to 2 seeds. Seeds: It produces small brownish seeds about 1/2 inch long joined with 3 papery disks as a trifoliate wing. Leaves: The leaves are square, variable, smooth, green, & dense. They are 80 to 90 cm long and 8 to 9 mm wide at the base. The end points are thin / acicular. The leaves form at the base with a spoon-shape that gives the plant its name. Found: Native to Northeast Mexico. in Mexico it grows to the south of the State of Nuevo Leon and to the southwest of Tamaulipas. Hardiness: Said to be hardy to 15�F. USDA Zone 8b: to -9.4 �C (15 �F) USDA Zone 9a: to -6.6 �C (20 �F) USDA Zone 9b: to -3.8 �C (25 �F) USDA Zone 10a: to -1.1 �C (30 �F) USDA Zone 10b: to 1.7 �C (35 �F) Soil pH requirements: 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline) 7.9 to 8.5 (alkaline) Sun Exposure: Full Sun Light Shade Elevation: 5,905 - 6,562 Feet. In native habitat. Will grow to about 0 - 6,562 feet in Arizona. Habitat: In it's native areas it grows on rocky slopes or in a flat, bushy terrain, associated with Yucca carnerosana , Agave lechuguilla , Agave striata and other species. It needs good drainage and aeration. Takes full sun; takes reflected heat. It grows well at low elevations in Arizona as well as at its normal range. Drought tolerant and cold hardy to at least 15 � F. Miscellaneous: Maintenance: Low. Photos Taken Boyce Thompson Arboretum, October 11, 2006. This plant will grow just about anywhere in Arizona.