27 August 2017

Favourite Nectaring Plants #12

Butterflies' Favourite Nectaring Plants #12
The Elephant's Foot (Elephantopus scaber)

In our 12th article of the Butterflies' Favourite Nectaring Plants series, we feature a rather low profile 'weed' that can be considered quite common where it occurs in Singapore. However, it is not as widespread as many other wild-flowering weeds that butterflies have been known to feed on. This perennial weed, called the Elephant's Foot (Elephantopus scaber) grows wild in open grassy areas, usually under some shade.

A honey bee taking nectar from the flower of the Elephant's Foot

The Elephant's Foot occurs in grasslands, wasteland, roadsides, along fields and in forest borders, an across its range at at elevations even up to 1,500 metres, which makes it a montane species as well! It is a common weed amongst lawns and is usually not welcome in manicured gardens, where it is usually pulled out and thrown away. It has dark green elongated leaves arranged in a rosette at the base.

The Elephant's Foot has many chemicals that are used in traditional medicine for a variety of ailments

Whilst doing research on this humble weed, I found a lot of material regarding the ethnomedicinal uses in various Asian cultures and further research showed that the chemical constituents extracted from various parts of this plant have antibiosis, antivirus, and cytotoxicity qualities. The chemical compounds from the Elephant's Foot used in traditional Chinese herbal medicine is used to treat multiple ailments ranging from headaches, conjunctivitis, eczema, cirrhosis, colds, diarrhea, hepatitis, and bronchitis.

The Elephant's Foot grows its rosette leaves flat and hugs the ground closely

The flowers grow on vertical stems which split into branches, each yielding more flower heads

The Malays believe that since the leaves of the Elephant's Foot lies flat on the ground and resemble the pentacle seal of Solomon, it suppresses the jins and confines them underground. In Indonesian traditional medicine , the plant is believed to be one of the ingredients used to prepare the local concoction of herbs known as "jamu".

Anderson's Grass Yellow feeding on the purplish-pink flower of the Elephant's Foot

The extracts from the leaves of this plant are also used as an aphrodisiac. Interestingly, it is one of several herbal constituents that are mixed to produce drugs that can perk up a male's flagging libido! In this particular advertisement for a natural herbal remedy for men, called Vitroman Powerplus, it is touted to cure erectile dysfunction or impotence! This Thai product uses herbal extracts from Elephant's Foot (Elephantopus scaber), Ginger (Zingiber officianale) and Red Kwao Krua (Butea superba) in combination with other herbs in a secret remedy that is believed to rival Pfizer's Viagra!

Plant Biodata :
Family : Asteraceae (Compositae)
Genus : Elephantopus
Species : scaber
Synonyms : Elephantopus carolinensis, Elephantopus sordidus
Country/Region of Origin : Tropical America, Africa, Asia, Australia
English Common Names : Elephant's Foot, Bull's tongue, Ironweed
Other Local Names : Tutup Bumi, Tapak Sulaiman, Anashovadi, 地胆草, 苦地胆, 鹿耳草(海南)

Hundreds of flowers of the Elephant's Foot blooming at an open grassy site

In Singapore, the Elephant's Foot can be found in open wastelands, grassy patches and fringes of nature reserves. It can also make its way into urban parks and gardens, and into the domestic gardens of landed properties, where it is an unwelcome invader (and treated as such). Where it occurs, it can be very common, often smothering a patch of grass and covering an entire area with its rosette-shaped form and vertical stems which bear its flowers.

A typical rosette form of an Elephant's Foot plant with its long green serrated-edged leaves and green midribs

Elephant's Foot leaves with purple mid-ribs and veins

The leaves range between 5-18 cm long and 2-4 cm wide. They are spatulate (spoon-shaped) or oblanceolate (lance-shaped with the wider end closer to the tip). They are arranged in a rosette-like shape and closely hug the ground. The leaves are a deep forest green in colour and hairy on both the upper and under surfaces. The margins are serrated and uneven. The mid-rib is thick and prominent, and is usually lighter green than the leaves. At times, the veins can be dark purplish in colour.

The flower head of the Elephant's Foot with its boat-shaped bracts

A vertical stem extends out (up to 30-40 cm) where it ends with 3 boat-shaped bracts holding the purple flowers. The stem branches dichotomously (splitting into 2 parts). It is densely covered in stiff, white hairs that are flattened against the stem surface. The compound inflorescence is composed of many capitula (compound flowers composed of 4, purplish or pink florets). The floret is composed of 8-10 mm long petals which form a 4-5 mm long tube.

The fruits are dry, one-seeded achenes about 4mm long and widened at the base. They are elongated, angled and covered in soft hairs. The fruit is attached to a pappus which is composed of 5-6, white bristles. The bristles cling on to animals, birds and humans walking past them and the dispersal of these seeds are believed to be via transmission by this method.

The roots are fibrous and reach down into the soil from the centre of the rosette form, reaching a depth of about 20cm. Propagation is usually by seeds and the plant is robust and can tolerate sandy soil and dry conditions, and is easy to grow.

The pretty purplish-pink flowers of the Elephant's Foot

Due to the diminutive size of the purple flowers, I have only seen the smaller species of butterflies feeding on the flowers. Perhaps it is the depth and physical size of the flowers that may only allow species with shorter and thinner proboscis to reach the nectar within them. I have not seen any of the larger species like the Papilionidae and Nymphalidae feeding on the flowers of the Elephant's Foot.

Examples of the Pieridae known to feed on the flowers of the Elephant's Foot

Amongst the Pieridae, the Eurema species have more often been seen feeding at the flowers. Examples are the Chocolate Grass Yellow, Anderson's Grass Yellow and Common Grass Yellow. I have not come across the larger Pieridae feeding on this plant's flowers. The Psyche (Leptosia nina malayana) another small butterfly, also feeds on the flower of the Elephant's Foot.

Top : Malayan Five Ring and Bottom : Common Four Ring feeding on the flowers of the Elephant's Foot

The Ypthima species often come to the flowers of the Elephant's Foot, and feed greedily on the open flowers. However, trying to photograph butterflies feeding on the flowers of this plant will prove to be a challenge as the flower heads are usually at 20-30cm from the ground, and the butterflies tend to be skittish and fly away at the slightest disturbance of their meal.

Common Caeruleans feeding on the flowers of the Elephant's Foot

Amongst the Lycaenidae, I have seen the Common Caerulaean, Common Hedge Blue and Lesser Grass Blue feeding on the flower of the Elephant's Foot. It is curious as to why there are not more Lycaenidaes that feed on the flowers of this plant. The physical size of the Lycaenidae should theoretically suit this flowering weed, but it is quite rare to see any other species, other than the ones mentioned here, feeding on the flower of the Elephant's Foot.

Examples of small Skippers that feed on the flowers of the Elephant's Foot

For the Hesperiidae, again only the smallest skippers have been seen at the flowers of the Elephant's Foot. Amongst those seen are the Chestnut Bob, Starry Bob, Spotted Grass Dart and Yellow Grass Dart that fly swiftly from flower to flower of the plant, and feeding on the open purple flowers.

The Elephant's Foot flowers appear to only bloom towards noon when the sun is up high in the sky

An interesting point to note about the Elephant's Foot, is that in the early morning hours, the purple flowers are hidden deep inside the flower head. When the sun warms up the environment, usually from 11:30am onwards and towards noon and throughout the afternoon, the purple flowers open up attractively, and this is when the butterflies are most active feeding on the flowers.

Text by Khew SK : Photos by Khew SK, Koh CH and Neo TP

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