The Portuguese Sundew Part 1
Kamil Pasek, Czech Exotic Plant Society
The Portuguese Sundew (Drosophyllum lusitanicum Link.) in nature and cultivationJan Flísek & Kamil Pásek
H. F. Link described the Portuguese Sundew (Drosophyllum lusitanicum Link.) in 1806, but the first references have been dated back to the 17th century. The genus name, Drosophyllum, is derived from the Greek DROSOS (meaning dew) and PHYLLON (meaning tribe or leaf). The species name is derived from Lusitania (from Latin), the ancient name for Portugal. In its native habitat, Drosophyllum is relatively rare, with plants growing in narrow coastal or maritime regions (maximum of a few tens of kilometers from the coast) with regular morning fogs during summer. Besides Portugal, Drosophyllum has been found in Andalusia (southwestern Spain) and in northern Morocco. Drosophyllum lusitanicum is the only extant species classed in the new monotypic genus of the family Drosophyllaceae Chrtek et al., 1989, 1996). The listed number of chromosomes is 2n = 12 (Heubl et al., 1997).
Drosophyllum lusitanicum is shrub-like carnivorous plant that can grow to be 1.5 m in height, but is usually shorter (about 40 cm). The stem is 5-15 mm thick and creeps along the ground when it becomes longer. The narrow, triangular leaves typically reach lengths of 10-25 cm with a width of 2.5 mm. The leaves can be longer in cultivation. Ten or more needle-like leaves are generally found per apical rosette. Older plants may develop side branches (or stems) during seed production, when suppressed buds in the leaf axils start to grow. These new side branches develop on both the long, ligneous and very sturdy stems of mature plants as well as on young plants. The rosette of leaves are typically 20 - 40 cm in diameter and consist of the apical "crest" of living leaves and dead leaves drooping down to the ground forming a dense tangle. With a little imagination, we see why the English common name "dewy pine" is used for this plant, as it looks very much like a small pine. The Portuguese call this plant "Pinheiro baboso", which, translated means "slobbering" pine (Porto, personal communication). Native people of southern Spain in the Alcala de los Gazules region call it "La Gazul" (Schmidt, 1997). Drosophyllum is a perennial in nature and cultivation, but precise information about the maximum lifespan of this plant has not yet been published.
The Portuguese Sundew is a very interesting and curious plant for several reasons. Compared with other carnivorous plants, it is one of the most successful "hunters" in terms of quantity of captured prey, and all with absolutely passive primitive adhesive traps (stalked clammy glands) only. Also, there are certain morphological and anatomical curiosities particular to Drosophyllum. Some observations indicate that Drosophyllum is more archaic than previously assumed, an unusual fact considering its classification within advanced flowering plants (Magnoliophyta). Morphological features (missing specific dividing coir - cambium an endodermis in the stem, characteristic surface of stem, shape of leaves, spirally twisted ends of leaves, etc.) indicate that Drosophyllum may be closely related to ferns (Studnička, 1984b).
Drosophyllum is interesting in that it has two types of glands on the leaves; the huge stalked glands that attract and trap prey and the sessile, digestive glands (Juniper et al., 1989). Production of the mucilage for trapping