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Plant Highlight: Asphodelus aestivus
Family concepts in the botanical world have undergone much change in recent years, and no group has been re-arranged more than the Lily Family, or Liliaceae. As formerly defined, this was a huge group including such diverse plants as lilies, hyacinths, asparagus, yuccas and aloes. Although the basic structure of the flowers is very similar in each of these examples, we now place each one in a different family in keeping with the trend towards smaller and more cohesive family groupings.
Among the splinter families from the old Liliaceae is the Asphodelaceae, or Asphodel Family. Included here are popular garden plants such as Kniphofia (Red-Hot Poker) and Bulbinella, as well as Aloe and its close kin. Some would continue dividing and put the latter into a still smaller family – Aloeaceae – but at RBG, we are content to include them in the Asphodelaceae.
The Asphodelaceae takes its name from Asphodelus, a genus whose members have clumps of narrow tapering leaves and spires of flowers in the white-to-pink range. Plants in this genus are found as far west as the Canary Islands in the Atlantic Ocean, and as far east as India, but most occur in the Mediterranean region. It should be noted that plants of the related genus Asphodeline are also commonly referred to as “Asphodel”.
Asphodelus aestivus occurs from the Canary Islands eastward through the Mediterranean basin. The term “aestivus” refers to its summer dormancy, a trait common in the Mediterranean area, with its rainy winters and dry summers. The plants have blue-green relatively narrow leaves which reach a length of about 2½ feet (75 cm). The leaves are keeled on the underside and guttered on the upper surface, much like those of Red-Hot Pokers. They arise from underground rhizomes, which branch to form clumps. The flowers emerge early in the year (the flowering period is Feb.– Mar. at RBG), with the stalks rising to a height of 4 to 5 feet (about 1½ m) or more. The stalks may be unbranched, but often they bear short side branches. The flowers are about an inch or so long (2½ – 3 cm), and the spreading petals (tepals) are white with a narrow brown stripe running down the middle.
At the end of the 20th century, advances in DNA testing led to a major re-assessment of the classification of monocots. The huge assemblage known as the Lily Family (Liliaceae) was a major casualty in all of this, chopped into numerous smaller families. One of the newly created families was the Asphodel Family, Asphodelaceae. The type genus of this group, from which its name is derived, is Asphodelus, containing about a dozen species of bulb-like plants with clumps of long narrow leaves. These are mostly native to the Mediterranean area, from the Canary Islands eastward along both sides of the Mediterranean Sea. In keeping with the winter-rainfall climate which prevails in this region, they often go dormant during the dry summer months. White is the most common flower color.
At the Ruth Bancroft Garden, we have a single species of asphodel, Asphodelus aestivus. In nature, it has a wide distribution around the Mediterranean. Its blue-green leaves grow to be 2 to 3 feet long (up to 1 m), or sometimes even longer, channeled on top and with a pronounced keel below. They are about ¾” (2 cm) wide, tapering gradually toward the tip. This plant is dormant in summer, with the new leaves emerging from the large tuberous root in fall, in response to the arrival of our winter rains. It flowers early in the year, mostly in February and March, with a branched flower stalk rising to a height of 3 to 4 feet (to about 1.25 m), bearing conical clusters of flowers. The star-like flowers are white, with 6 tepals (this term is used when the distinction between petals and sepals is ambiguous). A narrow brown stripe runs down the center of each tepal.
By the time the heat of summer sets in, the small black seeds have ripened and the leaves wither. The plants remain dormant until a new growth cycle begins with the resumption of rains in autumn.