Several plant species in the fynbos are sticky, whether in their stems, leaves, or flowers, and this characteristic is often reflected in their scientific names. One such plant is Moraea bituminosa, a member of the iris family known for its very sticky flowering stems. The specific name bituminosa is derived from the Latin word for tar or pitch, though the stems are only sticky, and not black like tar.
In addition to its sticky stem, Moraea bituminosa is easily recognized by its highly branched inflorescence, which features several yellow flowers with spreading petals and prominent crests on the styles at the centre of each flower. It is one of the later-flowering Cape Moraeas, blooming from late October into November. These plants add a splash of late spring color to the fynbos, though you’ll need to wait until the afternoon to see them open, as they only bloom after midday. The species is common on the lower slopes of Phillipskop and its range extends southward toward Bredasdorp and northward toward Tulbagh.
The stickiness of the stems in Moraea bituminosa is likely a defense mechanism against insects, rather than a carnivorous trait like that of Drosera. Many insects target flowers, the softest part of the plant, to feed, and the sticky stems make it dangerous for them to hold onto while eating. The sticky surface also prevents non-flying nectar robbers from reaching the base of the flower, where they might chew to access the nectar. While flying insects can still pollinate the flowers without issue, any unwary insect that lands on the stem can quickly become trapped.
Moraea bituminosa belongs to a subgenus of Moraea characterized by sticky stems and branched inflorescences, traits reflected in its name: Subgenus Visciramosae (sticky-branched). Another species from this section, found at Phillipskop and in the Klein River Mountains, blooms around the same time but is much harder to spot. Its name, Moraea inconspicua, reflects its inconspicuous nature. Unlike Moraea bituminosa, the flowers of Moraea inconspicua are smaller and have a dull brown-and-cream coloration. The visual size of the flowers is further reduced by the backward-swept petals, making the central disc the only visible part when viewed from above. Although difficult to spot, Moraea inconspicua is actually a widespread species, found throughout much of the Cape Floristic Region.
