Yuccas (Spanish Bayonet; Soapweed; Adam’s Needle)

1 of 6

Spanish Bayonet (Adam’s Needle) (Flowers)

2 of 6

Spanish Bayonet (Adam’s Needle) (Leaves)

3 of 6

Spanish Bayonet (Adam’s Needle) (Dried Fruit Capsules)

4 of 6

Spanish Bayonet (Adam’s Needle) (Leaves)

5 of 6

Spanish Bayonet (Adam’s Needle) (Green Fruit Capsules)

6 of 6
Three species in the genus Yucca in Missouri.
Agavaceae (agaves)

Spanish bayonet, or Adam’s needle (Yucca smalliana; formerly Y. filamentosa or Y. flaccida), has stout, scaly flower stalks topped by a panicle of many flowers, arising above a large basal cluster of stout, sharp-pointed, leathery leaves. Flowers cuplike with 3 sepals and 3 petals, 2 inches across, creamy white. Blooms May–July. Leaves basal, stiff, narrow, sharply pointed, to 2½ feet long, often with fibrous edges. Fruit a large, papery capsule with hundreds of flat, black seeds.

Soapweed (Yucca glauca) is a native found only in the northwestern corner of Missouri (Holt and Atchison counties). The base of the flowering portion of the flower clusters is not raised above the leaves, and the leaves are spine-tipped.

Another soapweed, Y. arkansana, is a native found only in the southern portion of Missouri’s Ozarks, along the Arkansas border. It is similar to Y. glauca, but it has softer leaves that are not spine-tipped.

Height: to about 7 feet (flowering stalk).
Habitat and conservation: 
Spanish bayonet occurs on roadsides, railroads, abandoned homes, and gardens. It is native to the southwestern United States, introduced here and escaped from cultivation. Of our two native soapweeds, Y. arkansana is found in glades, open rocky woods, and roadsides, and Y. glauca is uncommon, for it is a plant of the few remaining loess hill prairies in the state.
Distribution in Missouri: 
Spanish bayonet is scattered statewide. Our two native soapweed yuccas are restricted to northwestern counties (Y. glauca) and to southern counties (Y. arkansana).
Human connections: 
Yuccas are tremendously useful. The roots of some species have been used in soapmaking (thus the name "soapweed"), and the seeds have been eaten raw, roasted, or ground into a flour. The tough leaves provide fiber for cordage and broom-making. Today, yuccas are valued by landscapers.
Ecosystem connections: 
Only a certain type of moth can fertilize yuccas, which occurs as the female moth deposits eggs into the flower’s ovary. The growing caterpillars eat some, but not all, of the plant's seeds. A Missouri entomologist, Charles V. Riley, discovered this trade-off between plant and insect.
Shortened URL