Sporobolus jacquemontii

rat's tail grass


Sporobolus jacquemontii

Kunth. 1831

pronounced: spor-ROB-of-luss jack-MON-tee-eye

(Poaceae — the grass family)


common names: rat's tail grass, wire grass

Sporobolus is derived from the Greek σπορα (spora), seed sown, and βολος (bolos), a throwing, alluding, presumably, to the way the seed is forcibly released in some species of this grass; jacquemontii was named for Victor Jacquemont (1801 – 1832), French traveller and naturalist. He studied botany in Paris before visiting North America and Haiti. From there he planned a scientific voyage to the East Indies, as naturalist and traveller to the Paris Museum of Natural History. After returning to France, and visiting England, he set out for Calcutta, where he arrived in May, 1829; and, after learning the basics of several Indian languages, set out on his travels. After visiting some of the English provinces, he explored the Himalayas towards Tibet, and penetrated as far as Chinese Tartary. In the kingdom of Lahore, he was offered the post of Viceroy in Cashmere, but he preferred to continue his travels. He died of a disease contracted while travelling through the pestilential forests of Salsette Island. After his death, his letters home to his friends were published as Letters from India (A. D. 1828 – 1831) India, Tibet, Lahore and Cashmere – 2 vols. This is one of the most attractive and original books of travels ever published. The diary of his Voyage dans l'Inde pendant les annees 1828 à 1832 (6 vols.), published at the expense of the French government, embodies a large amount of valuable zoological and botanical observations. There is a painting by Claude Monet, the French Impressionist, entitled 'Victor Jacquemont holding a Parasol'. The subject of this painting is generally thought to be our naturalist, but, as Monet was not born until after Jacquemont’s death, and the paining was not done until 1865, it cannot have been a painting from life, and it is very unlikely that there would have been in existence a photograph of the naturalist. If, indeed, it is a paining of our man, it must have been done either from someone else’s sketch, or from a description.

Sporobolus is a genus of perennial or annual grasses, erect to decumbent, usually tufted. The glumes are unequal, the lower glume often being very short. The mature grain becomes sticky when wet. They are often called ‘drop-seed grasses’ or ‘sacaton grasses’. They are typical prairie and savannah grasses, but are generally considered to make inferior pastures, as evinced by some of the common names of their species, e.g. poverty grass, smut grass. On the other hand, seeds of at least some species are edible and nutritious, and were used as food by some of the North American Indian tribes. Other species are reported to be used as famine foods, especially Sporobolus indicus in parts of Ethiopia.

Sporobolus jacquemontii is a non-native grass that can tuft densely, and grows to about 75 cm tall. It is a common weed in many Townsville and Magnetic Island lawns. It can also easily invade pastures, and replace more productive types of grass. It is a Class 2 declared plant under Queensland legislation.

The ligule is a fringe of hairs. The inflorescence is usually compact, with the primary branches of the panicle 5 – 10 cm long. The spikelets have one floret, pale to dark green in colour.

The species of this genus are notoriously difficult to tell apart: but, if it is growing in your lawn, it’s probably this one!


Voyage in the Indies during the years 1828 - 1832

Photographs taken 2010, Picnic Bay
Page last updated 7th April 2019