Pay a visit to the Granada Native Garden soon, before this is gone! With its sensational 10-15 foot tall flower stalk, viewed from a distance, Hesperoyucca whipplei can resemble a candle with a creamy white flame. It takes 5-10 years from the time of planting for Our Lord’s Candle to reach maturity and produce a flower stalk. But once it reaches this point, the stalk can suddenly pop up in a matter of about two weeks. (Note: Most photos can be enlarged by clicking on them.) Another name for this plant, however, is “Spanish Bayonet”. This is because the leaves, which form a dense rosette at ground level, are stiff and narrow, have saw-toothed edges, and terminate in a very sharp point similar to a cactus needle. So view it from a safe distance! Some Native Americans used a yucca needle for ear-piercing and tattooing. Bert Wilson of Las Pilitas Nursery suggested a novel use for this plant: a hedge of them planted around a prison could take the place of an 8-foot wall capped with razor wire or broken glass, and be “a great deal more neighborly”. (This is the third time in the past six years that our specimen has produced a flower stalk. However, the first two times, vandals broke it down and left it lying on the ground. How they did this without getting impaled on the leaves is unclear to me! )
A Striking Example of Symbiosis The upper third or one-half of this spike consists of a spectacular display of hundreds of white to purplish flowers, several feet long. The blossoms are pollinated at night by the California yucca moth (Tegeticula maculata). The female moth collects sticky pollen grains from the blossoms of one plant and forms them into a massive ball on the underside of her head. She then flies to a blossom of another plant and inserts a single egg into the ovary of the blossom. She rubs the mass of pollen against the ovary, thus fertilizing the ovary. The ovary will now produce many seeds which develop into fruits. When the moth larva emerges from its egg, it feeds on the fruits, most of which remain uneaten and are capable of producing new plants. Thus both the plant and the moth benefit from this relationship, which is called symbiosis. When the larva matures, it burrows out of the fruit, metamorphoses into an adult moth, and the cycle continues. Over evolutionary time, yucca moths and yuccas have evolved complete mutual dependence on each other (“obligate mutualism”).
Two Ways to Reproduce Itself After the flowers have been pollinated (sexual reproduction), the Hesperoyucca whipplei plant slowly dies, altho the flower stalk may remain in place for several more years (unless some ignorant burnouts come along). However, rosettes of new plants grow out at the base of the old plant (asexual reproduction). Hespero- yucca whipplei is native to the south- ern part of California and Baja Cali- fornia. If it is planted in a part of the state where yucca moths are not native, the plant might have to rely on new rosettes for reproduction. Over time the rosettes accumulate to form an impenetrable barrier to foot traffic (but also present a serious hazard to the unsuspecting, especially children, because of their sharp leaf tips).
Native American Uses of Hesperoyucca whipplei Among the Native Americans, the stiff leaves of Our Lord’s Candle provided fiber for making sandals, cloth, fishing lines, nets and rope. The flowers and the stalk are edible. The seeds were roasted and eaten whole or ground into flour. When the seeds mature into fruits, they can be eaten raw, or roasted, or pounded into meal. In 1769, the Spanish soldier and explorer Pedro Fages reported that the roasted plant “is juicy, sweet, and of a certain vinous flavor; indeed a very good wine can be made from it.”
Pop Quiz! Without looking back, can you explain what is meant by the relationship called “symbiosis”? Also, can you explain why this example of symbiosis is also called “obligate mutualism”? Also, make sure you understand the difference between sexual and asexual repro-duction so that you can explain it to someone else (especially to a young person!). If you aren’t sure, study that paragraph again carefully.
Quote du Jour “If we humans are capable of turning hundreds of millions of acres of rainforest into depleted grasslands, and extirpating millions of buffalo from the plains, and billions of passenger pigeons from the skies and cod from the North Atlantic, we are also capable of returning native plants and insects to our gardens.” – Douglas W. Tallamy, Bringing Nature Home