Pennisetum

Pennisetum is a widespread genus of plants in the grass family, native to tropical and warm temperate regions of the world. They are known commonly as fountaingrasses (fountain grasses). Pennisetum is considered a synonym of Cenchrus in Kew's Plants of the World Online.

Taxonomy
Pennisetum is closely related to the genus Cenchrus, and the boundary between them is unclear. Cenchrus was derived from Pennisetum and the two are grouped in a monophyletic clade. Some species now in Pennisetum were once members of Cenchrus, and some have been moved back. A main morphological character used to distinguish them is the degree of fusion of the bristles in the inflorescence, but this is often unreliable. In 2010, researchers proposed to transfer Pennisetum into Cenchrus, along with the related genus Odontelytrum. The genus is currently not accepted as separate from Cenchrus in Kew's Plants of the World Online database.

Species
The World Checklist of Selected Plant Families lists the following species as synonyms of Cenchrus: • Pennisetum alopecuroides – Chinese fountaingrass, foxtail fountaingrass, swamp-foxtail – Australia, East + Southeast Asia

• Pennisetum annuum – Peru

• Pennisetum articulare – Marquesas

• Pennisetum basedowii – Australia

• Pennisetum beckeroides – Ethiopia

• Pennisetum caffrum – Madagascar, Réunion

• Pennisetum chilense – Chile, Argentina, Peru, Bolivia

• Pennisetum clandestinum – kikuyu grass – central + eastern Africa

• Pennisetum complanatum – Nicaraguan fountaingrass – Veracruz, Central America

• Pennisetum crinitum – Mexico

• Pennisetum × cupreum – New Guinea

• Pennisetum distachyum – Mexico, Costa Rica, Guatemala

• Pennisetum divisum – deserts from Mauritania to western India

• Pennisetum domingense – Cuba, Hispaniola

• Pennisetum durum – Mexico

• Pennisetum exiguum – Madagascar

• Pennisetum flaccidum – flaccid grass, Himalayan fountaingrass – Himalayas, Central Asia, China, Mongolia

• Pennisetum flexile – Kashmir

• Pennisetum foermerianum – Namibia

• Pennisetum frutescens – Paraguay, Argentina

• Pennisetum glaucifolium – Eritrea, Ethiopia

• Pennisetum glaucum – pearl millet, bulrush millet, cattail millet, horse millet, Indian millet, yellow bristlegrass

• Pennisetum gracilescens – Eritrea, Ethiopia, Sudan

• Pennisetum henryanum – Marquesas

• Pennisetum hohenackeri – Kenya, Tanzania, Uganda, Madagascar, India, Nepal, Pakistan

• Pennisetum hordeoides – western + central Africa, India, Nepal, Myanmar

• Pennisetum humile – Ethiopia

• Pennisetum intectum – Peru, Ecuador

• Pennisetum lanatum – Afghanistan, northern India, Pakistan, Tajikistan, Nepal, Tibet

• Pennisetum latifolium – Uruguay fountaingrass – South America from Colombia to Uruguay

• Pennisetum laxius – Sahel in Africa

• Pennisetum ledermannii – Cameroon

• Pennisetum longissimum – China

• Pennisetum longistylum – Eritrea, Ethiopia

• Pennisetum macrostachyum – Pacific fountaingrass – Java, Borneo, Papuasia

• Pennisetum macrourum – African feather grass, bedding grass, waterside-reed – Africa, Yemen, Saudi Arabia

• Pennisetum massaicum – Somalia, Kenya, Tanzania, Zimbabwe

• Pennisetum mezianum – Ethiopia, Sudan, South Sudan, Kenya, Uganda, Tanzania, Namibia, Limpopo

• Pennisetum mildbraedii – Rwanda, Zaire, Uganda

• Pennisetum monostigma – Sierra Leone, Nigeria, Cameroon, islands in Gulf of Guinea

• Pennisetum montanum – Peru, Bolivia, Argentina

• Pennisetum nervosum – bentspike fountaingrass – South America; naturalized in Belize, Nicaragua, Mexico, California, Texas

• Pennisetum nodiflorum – central Africa

• Pennisetum nubicum – Eritrea, Ethiopia, Sudan, Saudi Arabia

• Pennisetum occidentale – Venezuela, Colombia, Ecuador, Peru

• Pennisetum orientale – white fountaingrass, Oriental pennisetum – North Africa, Middle East, Central Asia, Indian Subcontinent

• Pennisetum pauperum – Ecuador incl Galápagos

• Pennisetum pedicellatum – annual kyasuwa grass, deenanth grass, hairy fountaingrass – Cape Verde, Africa, Madagascar, southern Asia from Arabia to Vietnam

• Pennisetum peruvianum – Venezuela, Colombia, Ecuador, Peru

• Pennisetum petiolare – petioled fountaingrass – Eritrea, Ethiopia, Sudan

• Pennisetum pirottae – Eritrea, Ethiopia, Sudan

• Pennisetum polystachion (L.) Schult. – feather pennisetum, mission grass, thin Napier grass – Africa, southern Asia from Arabia to Vietnam, Indian Ocean islands

• Pennisetum preslii – from Mexico to Peru

• Pennisetum procerum – Uganda, Kenya

• Pennisetum prolificum – southern Mexico

• Pennisetum pseudotriticoides – Madagascar

• Pennisetum pumilum – Ethiopia

• Pennisetum purpureum – Napier grass, Uganda grass, elephant grass, barner grass, Merker grass – Africa, Aldabra, Arabian Pen; naturalized in parts of Asia, Australia, Americas, various islands

• Pennisetum qianningense – Sichuan, Yunnan

• Pennisetum ramosum – central + eastern Africa

• Pennisetum rigidum – northern Argentina

• Pennisetum riparium – East Africa

• Pennisetum rupestre – Colombia, Peru

• Pennisetum sagittatum – Peru, Bolivia

• Pennisetum schweinfurthii – Ethiopia, Sudan

• Pennisetum shaanxiense – China

• Pennisetum sichuanense – Sichuan, Yunnan

• Pennisetum sieberianum – Africa

• Pennisetum sphacelatum – Africa, Comoros

• Pennisetum squamulatum – Eritrea, Ethiopia, Kenya, Tanzania

• Pennisetum stramineum – Eritrea, Ethiopia, Kenya, Tanzania, Yemen, Saudi Arabia

• Pennisetum tempisquense – Costa Rica

• Pennisetum thulinii – Ethiopia

• Pennisetum thunbergii – Africa, Yemen

• Pennisetum trachyphyllum – central Africa

• Pennisetum trisetum – central Africa

• Pennisetum tristachyum – South America

• Pennisetum uliginosum – Ethiopia

• Pennisetum unisetum – Natal grass, silky grass – Africa, Yemen, Saudi Arabia

• Pennisetum villosum R.Br. ex Fresen. – feathertop, long-style feathergrass, white foxtail – Africa, Yemen, Saudi Arabia; naturalized in New Zealand, Mediterranean, scattered places in Americas

• Pennisetum violaceum – Sahara, Sahel

• Pennisetum weberbaueri – Ecuador, Bolivia, Peru

• Pennisetum yemense – Yemen, Saudi Arabia, Eritrea

Description
As currently envisioned, Pennisetum is a genus of 80 to 140 species. The various species are native to Africa, Asia, Australia, and Latin America, with some of them widely naturalized in Europe and North America, as well as on various oceanic islands.

They are annual or perennial grasses. Some are petite while others can produce stems up to 8 meters tall. The inflorescence is a very dense, narrow panicle containing fascicles of spikelets interspersed with bristles. There are three kinds of bristle, and some species have all three, while others do not. Some bristles are coated in hairs, sometimes long, showy, plumelike hairs that inspired the genus name, the Latin penna ("feather") and seta ("bristle").

Uses
The genus includes pearl millet (P. glaucum), an important food crop. Napier grass (P. purpureum) is used for grazing livestock in Africa.

Several species are cultivated as ornamental plants, notably P. advena, P. alopecuroides, P. orientale, P. setaceum, and P. villosum. The cultivar 'Fairy Tails' is a recipient of the Royal Horticultural Society's Award of Garden Merit.

Ecology


Many Pennisetum grasses are noxious weeds, including feathertop grass (P. villosum) and kikuyu grass (P. clandestinum), which is also a popular and hardy turf grass in some parts of the world.

The herbage and seeds of these grasses are food for herbivores, such as the chestnut-breasted mannikin (Lonchura castaneothorax), the caterpillar of the butterfly Melanitis phedima, and the larvae of the fly genus Delia.

The genus is a host of the pathogenic fungus Cochliobolus sativus.