About Wahlenbergia capensis (L.) A.DC.
Wahlenbergia capensis is an annual herb that typically grows between 14 cm and 50 cm tall, with one main stem or just a few stems. Its lower leaves are egg-shaped to elliptic, and change to a lance shape higher up the stem. The leaves measure 9 to 40 mm in length and 1.5 to 10 mm in width, and sometimes have wavy edges with small teeth or lobes. Each individual plant produces up to four long-stalked flowers. These flowers are bluish-green overall, dark blue close to the center, and often marked with black spots. The five sepals are triangular, 4 to 7.5 mm long, and covered in fine hairs. The petals form a tube that is bell-shaped near the base, ending in five spreading, egg-shaped to broadly elliptic lobes. The entire petal structure is 6 to 11 mm long and 3 to 7.5 mm wide. The five stamens each have a 2.5 to 4 mm long filament and a 2 to 3.5 mm long anther. The style is dark blue, with five branches at its tip. This species flowers from September through December. It produces a capsule-shaped fruit that is 5 to 11 mm long and 5 to 9 mm wide.
Wahlenbergia capensis is widespread and endemic to the Western Cape region of South Africa, occurring between Clanwilliam and Knysna. It grows on lower sandstone slopes and sandy flats within this area. Because of its annual life cycle, it can also persist successfully on disturbed land, including roadsides and cultivated areas. It has been introduced as a non-native species to the south-west of Western Australia, where it grows between Kalbarri and Tambellup. This species was first collected in Western Australia in 1898.
In its ecology, the flowers of Wahlenbergia capensis are pollinated by monkey beetles. The seed capsules produce large numbers of seeds, and seeds are dispersed in two main ways. The first method relies on the region's strong summer winds, which shake seeds out through the apical valves of the capsule. Alternatively, the coarse, stiff hairs on the capsule can attach to the fur of animals, allowing the entire seed-filled capsule to be carried and dispersed.
