This showy Pelargonium with its dark pink flowers and dark green leaves will bring delight to a garden wanting striking contrast.
Pelargonium glutinosum is an erect, well-branched, balm-scented shrub, up to 1.8 x 1 m. It has soft herbaceous stems when young but becomes woody as it matures. The glabrous to villous glandular hairs on the stem are green when young and become brown with age. The leaves are glabrescent with numerous glandular hairs and are green to dark green. The inflorescence consists of 1-8 pale to dark pink flowers. It flowers sporadically throughout the year with peak flowering periods during spring, September to November. The species is extremely variable with regards to flowers and leaves. There are three forms that can be distinguished in this shrub. Plants from the western distribution areas have deeply incised leaves with pale pink flowers. The buds of the flowers have a distinctive pear-shape. Reinhard Knuth in 1910 described this as Pelargonium erectum. Populations from the Limpopo Province resemble this growth form although they display smaller flowers. In the Karoo distribution areas plants have dark pink flowers with leaves that are less incised. Plants from the eastern distribution range have dark pink flowers with shallowly incised leaves. The distribution of these three forms is by no means disorganized and a continuous variation in leaf and floral characteristics occur. It is therefore not possible to recognize infraspecific taxa although considerable differences exist between the extreme forms.
Pelargonium glutinosum is very common and therefore has no conservation status.
Distribution and habitat
Pelargonium glutinosum occurs from Piketberg in the Western Cape to as far as the Kei River in the Eastern Cape. It is also known from single populations, such as those occurring in the Soutpansberg in the Limpopo Province. The plants distribution pattern is largely associated to maintain ranges. It grows on well-drained soils in somewhat moist habitats and is often found close to running water. In the Karoo, which has a low annual rainfall, it is found in the mountainous area where the rainfall is much higher than the lower-lying areas. The rainfall plays little significance as the shrub is found in summer and winter rainfall areas or in areas that receive rainfall throughout the year. Temperatures in these areas can be high in summer and frost is also a possibility during midwinter in some of the inland regions.
Derivation of name and historical aspects
The genus Pelargonium derives its name from the resemblance of the shape of the fruit to the beak of a stork, pelargos in Greek. The species name glutinosum refers to the sticky leaves of the shrub. The genus Pelargonium belongs to the family Geraniaceae, a large family of 11 genera and 800 species in the subtropical and tropical world. There are 270 species of Pelargonium, which occur in S, E and NE Africa, Asia, St Helena, Tristan da Cunha, Madagascar, Australia and New Zealand; of this amount, 219 species occur in southern Africa.
The seed of pelargoniums is quite interesting: attached to the elliptically shaped seed, is a feathered, tail-like structure that is coiled in a spiral. The tail allows the seed to drill and secure itself in the soil if twisted around by the wind or affected by the movement of animals.
Uses and cultural aspects
No cultural uses have been recorded. Pelargonium glutinosum is ideal for any garden as it can withstand extreme temperatures and it flowers for most of the year. It needs a sunny spot in the garden and preferably as a background plant in a garden bed as this species grows quite tall.
Growing Pelargonium glutinosum
Pelargonium glutinosum can easily be grown from seeds and cuttings. Cuttings can be grown at any time of the year. Take semi-mature stem cuttings of 150 mm long and apply a rooting hormone to stimulate the rooting process. Insert them into prepared holes made by a wooden dibber or a nail to avoid damaging the ends. The cuttings are then placed in a coldframe to root. Rooting of this species usually takes about 3-4 weeks. Once the cuttings have rooted pot them in a well-drained potting soil mix. Feed the newly rooted cuttings with a liquid seaweed-based fertilizer.
Pelargoniums can also be grown from seed in late summer and early autumn. Sow the seeds in a light, well-drained potting soil. Broadcast the seeds evenly in the seed tray, covering them with a layer of clean white sand or fine-milled pine bark. The depth of sowing is usually one-and-a-half times the size of the seed. Water thoroughly but gently and provide light shade. Germination usually takes place within 4 weeks. Pelargoniums grown from seed are generally more vigorous than those made from cuttings. They do tend to take longer to produce flowers. Remember that plants grown from seed will show some degree of variation and if a particular form or variant is required it must be propagated vegetatively, by cuttings. The plant can grow easily in a garden where the soils are fairly damp and moist. It is relatively fast-growing, showy and long-flowering.
References and further reading
- Goldblatt, P. & Manning, J.C. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9. National Botanical Institute of South Africa, Cape Town and Missouri Botanical Garden.
- Van der Walt, J.J.A. & Vorster, P.J. 1988. Pelargoniums of southern Africa, vol. 3. Kirstenbosch National Botanical Gardens, Cape Town.
Kirstenbosch National Botanical Garden
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