Drosophyllum is a genus of carnivorous plants containing the single species Drosophyllum lusitanicum. In appearance, it is similar to the related genus Drosera, and to the much more distantly related Byblis. Drosophyllum lusitanicum is native to the western Mediterranean region, and is one of the fewcarnivorousplants to grow in dry soil. The 20- to 40-cm glandular leaves, which uncoil from a central rosette, lack the power of movement common to most sundews, but have the unusual characteristic of coiling 'outward' when immature. The plant has a distinct sweet aroma, which attracts the insects upon which it preys. When insects land on the leaves, they find themselves stuck to the mucilage secreted by the stalked glands on the leaves. The more the insects struggle, the more ensnared they become, ultimately dying of suffocation or exhaustion. The plant then secretes enzymes which dissolve the insects and release the nutrients, which are then absorbed by the plant. The plant uses these nutrients to supplement the nutrient-poor soil in which it grows. Drosophyllum lusitanicumbears bright-yellow flowers, in diameter, borne in groups of 3–15 between February and May. The translucent seedpods bear 3–10 opaque black, pear-shaped seeds, in diameter. Seed germination may be aided by scarification. The genus had always been assumed to be closely allied to Drosera, and was previously placed in the Droseraceae. Recent molecular and biochemical studies, however, place it in the monotypic Drosophyllaceae, as recommended by the Angiosperm Phylogeny Group, and allied with the Dioncophyllaceae and Ancistrocladaceae.
Classification
The APG system and APG II system assign Drosophyllaceae to the order Caryophyllales in the cladecore eudicots. D. lusitanicum had previously always been included in the family Droseraceae, as it catches insects with a method reminiscent of that used by many plants in that family. Recent molecular and biochemical evidence suggests the carnivorous taxa in the order Caryophyllales all belong to the same clade, which does not consist only of carnivorous plants, but also includes some noncarnivorous plants, such as those in the family Ancistrocladaceae.
