Yucca smalliana Fernald

Spanish Bayonet

Yucca_smalliana_plant.jpg
STATS

Introduced
CC = *
CW = 5
MOC = 1

© DETenaglia

Family - Agavaceae

Stems - Reduced to a woody base, to 20 cm long. Flowering stem to 2.5 m tall.

Leaves - All basal, linear, 15-80 cm long, 2-7 cm wide, somewhat glaucous, straight or lax, leathery, linear-lanceolate to linear-oblanceolate with a short, stout spine at the tip and white to tan, peeling, fibrous margins.

Yucca_smalliana_stem.jpg Leaves of the inflorescence axis.

© DETenaglia

Inflorescence - Large terminal panicle to 2.5 m, erect, with the base of the flowering portion raised above the leaves. Pedicels 1.1 cm long, densely pubescent.

Yucca_smalliana_inflorescence.jpg Inflorescence.

© SRTurner

Flowers - Tepals 5-7 cm long, ovate, the tips tapered to a point, green-or yellow-white, sometimes tinged pale purple, glabrous, succulent. Stamens 6, usually included, the anthers sagittate. Ovary superior, 3-locular, the style short, the stigma 3-lobed to nearly entire.

Yucca_smalliana_flower2.jpg Flower.

© SRTurner

Yucca_smalliana_flower.jpg Perianth.

© DETenaglia

Yucca_smalliana_flower_close.jpg Stamens and pistil.

© DETenaglia

Fruit - 6 angled capsule to 5 cm long, 3 cm in diameter. Seeds many, flat, 6-8 mm broad.

Yucca_smalliana_fruit.jpg Dehisced fruit.

© SRTurner

Yucca_smalliana_seeds.jpg Seeds.

© SRTurner

Flowering - May - August.

Habitat - Cultivated but escaping to various localities.

Origin - Native of southeastern U.S., considered introduced in Missouri.

Other info. - This species can be found cultivated throughout Missouri, sometimes escaping cultivation and often persisting around former habitations. It is very showy when in bloom and is easily recognizable. The species is distinguished from other yuccas found in Missouri by its paniculate (branched) inflorescences. However, specific identification, as well as discernment of native range, is complicated by widespread and sporadic presence of various unpredictable species and cultivars due to past cultivation events.

The leaf fibers of various Yuccas and Agaves can be mechanically extracted and used to make rope with very high tensile strength.

Yuccas in the central U.S. have a extraordinary relationship with moths in the Prodoxidae family, with each species of yucca typically associated with a single species of moth. The moths are the only known pollination vector for the plants, and the plant seeds are the only known food source for the moth larvae, which hatch from eggs laid within the plant ovary. The moth and the plant are absolutely interdependent for survival. In many cases, the behavior of the moth is strongly suggestive of deliberate pollination of its host plant.

Yucca_smalliana_pollinator.jpg Yucca pollinator moth, possibly Tegeticula yuccasella or similar.

© SRTurner

Photographs taken off Hwy 60 near Van Buren, MO., 6-5-04 (DETenaglia); also at Weldon Spring Conservation Area, St. Charles County, MO, 6-24-2011 and 6-20-2016, near Labadie, Franklin County, MO, 6-7-2019, and Pea Ridge Conservation Area, Washington County, MO, 2-23-2020 (SRTurner).