Ipomoea pes-carpae (Goat's Foot, Railway Vine)
Ipomoea pes-caprae is a trailing, ground-covering vine which is a member of the morning glory family Convolvulaceae. It has a wide distribution being native to the coastal sand dunes of tropical and sub-tropical countries boarding the Pacific, Atlantic and Indian oceans. The seeds of this species float and can survive immersion in salt water and these two features are the reason it has such a large distribution, this plant is spread via the sea.
Ipomoea is the same genus that other commonly grown garden morning glories belong to and means ‘worm-like’ which is in reference to the way the flower buds are coiled before opening. The species epithet pes-carpae means ‘stalk-fruit’, a reference to the fruit which are borne on individual stalks. The plant goes by a variety of common names, including Coastal Morning Glory, Railway Vine, Goat’s Foot Vine and Bayhops as well as a variety of regional names.
The common name of Goat’s Foot Vine is a reference to the shape of the leaves of Ipomoea pes-caprae. They have a distinctive cleft at the tip of the leaf which gives the leaf when flattened the appearance of a footprint of a goat’s hoof. The two halves of the leaf are folded together partially along the mid-vein and have a long petiole (leaf stalk).
The individual vines arise from a central, woody underground root system and the vines can regrow from this when cut. The vines also send out additional roots to anchor themselves to the ground from the underside of where the leaf arises at each note. The sap of this plant is milky like other morning glories.
In the wild Ipomoea pes-carpae acts as a pioneer species of sand dunes, being one of the first colonisers of empty dunes, and are important as their root system helps to stabilise the dunes and prevent them from washing away into the sea during heavy storms.
The flowers are typical of plants in the morning glory family, and are large (5cm in diameter) and attractive. The flowers are trumpet shaped and the petals and carpals are fused together to form a continuous bell. The petals are of a light mauve colour with the sepals and throat of the flowers being a darker purple colour. The flower petals are thin and delicate and flowers only last a few days each.
Ipomoea pes-caprae has at least one medicinal use. In traditional Brazilian herbal medicine it is used to treat problems with the digestive system and reduce swelling. I’m uncertain of the exact method of preparation for this and it was a Brazilian sub-species (Ipomoea pes-caprae subsp. brasiliensis) that was used, so it’s probably best to avoid trying to make use of the medicinal properties of any plants grown at home.
Although Ipomoea pes-caprae is a creeping vine, it’s not vigorous to the extent that other vines can be and while it’ll grow reasonably quickly, it’ll rarely out-compete and smoother other plants. The leaves are sparsely spaced along the running vines and let plenty of light in around them for other plants to utilise. In its natural environment, it can often be found growing in mixed patches with other coastal groundcover species.
Being a coastal plant, Ipomoea pes-caprae has some useful benefits when grown in the home garden. It is naturally tolerant of salt spray and windy conditions. Although it needs to be grown in a soil that is very free draining, it doesn’t need to be planted in pure sand. The leaves and stems are slightly succulent which helps the plant to store water for dry periods.