Cenchrus setaceus ‘Rubrum’ (Syn. Pennisetum setaceum) (Purple Fountain Grass)

Cenchrus setaceus ‘Rubrum’ after I brought it home on 6-7-18, #455-19.

Purple Fountain Grass, Etc.

Cenchrus setaceus ‘Rubrum’

SENCH-rus   se-TAY-see-us

Syn:

Pennisetum setaceum ‘Rubrum’

pen-ih-SEE-tum   se-TAY-see-um

ROYAL HORTICULTURAL SOCIETY’S AWARD OF GARDEN MERIT

Synonyms of Cenchrus setaceus (16) (Updated on 12-22-23 from Plants of the World Online): Pennisetum erythraeum Chiov. (1903 publ. 1902), Pennisetum macrostachyon Fresen. (1837) ( non P. macrostachyum Trin.), Pennisetum numidicum Paris (1871) (nom. nud.), Pennisetum orientale var. altissimum Chiov.(1897), Pennisetum orientale subsp. parisii Trab. (1887), Pennisetum orientale var. parisii (Trab.) Leeke (1907), Pennisetum parisii (Trab.) Trab. (1895), Pennisetum phalaroides Schult. (1824) (nom. superfl.), Pennisetum rueppelianum Hochst. ex Penz. (1893) (nom. superfl.), Pennisetum ruppellii Steud. (1841), Pennisetum ruppellii var. depauperatum Schweinf. (1894), Pennisetum scoparium Chiov. (1903 publ. 1902), Pennisetum setaceum (Forssk.) Chiov. (1923), Pennisetum spectabile Fig. & De Not. (1852), Pennisetum tiberiadis Boiss. (1854), Phalaris setacea Forssk. (1775)

Cenchrus setaceus (Forssk.) Morrone is the accepted scientific name for this species. It was described as such by Osvaldo Morrone in Annals of Botany (Oxford) in 2010. It was first named and described as Phalaris setacea by Pehr Forsskål in Flora Aegyptiaco (Arabia) in 1775.

Pennisetum setaceum has been regarded as the scientific name for the Purple Fountain Grass for MANY years. The industry still uses this name on their labels and many websites still use this name. 

Pennisetum setaceum (Forssk.) Chiov. was described by Emilio Chiovenda in Bullettino della Società Botanica italiana in 1923. 

The genus, Cenchrus L., was described by Carl von Linnaeus in the second volume of the first edition of Species Plantarum in 1753.

The genus, Pennisetum Pers., was named and described by Christiaan Hendrik Persoon in Synopsis Plantarum in 1805.

There has been a long debate between the Cenchrus and Pennisetum generas and many species have been moved back and forth for many years. The page on Wikipedia says, 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 not accepted as separate from Cenchrus in Kew’s Plants of the World Online database.”

As of 12-22-23 when this page was last updated, Plants of the World Online lists 107 species in the Cenchrus genus. It is a member of the plant family Poaceae with 793 genera. Those numbers could change as updates are made on POWO.

Formerly, the Pennisetum species included various grasses and grains and is commonly referred to as the fountain grass family. The Cenchrus genus is a family of buffalo grasses, sandburs, and sand spur. In other words, members of one genus are loved and the other hated. 🙂 I hesitated to completely change the genus and species name here because names keep changing back and forth and become synonyms of one or the other. But, since the name stuck for a while I decided to go ahead and change it. Keep in mind, just because many websites use the other names it doesn’t mean they are wrong. They can use whatever name they choose as long as they were validly published.

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING.

Cenchrus setaceus ‘Rubrum’ (Purple Fountain Grass) on 6-11-18, #458-4.

I brought this Purple Fountain Grass home from Muddy Creek Greenhouse on June 7, 2018. I put it in the bed on the left side of the porch on the northeast corner of the house. 

Cenchrus setaceus ‘Rubrum’ (Purple Fountain Grass) on 7-13-18, #477-2.

USEFUL INFORMATION:
Family: Poaceae
Origin: Africa, Southeast Asia, Middle East
Zones: USDA Zones 9a-11b (20 to 40° F)
Size: 3-5’ tall x 2-4’ wide
Light: Sun to part shade
Soil: Medium, well-drained soil
Water: Average

Cenchrus setaceus ‘Rubrum’ (Purple Fountain Grass) on 7-13-18, #477-3.

Typically grown as an annual outside USDA Zones 9-10, they will not survive the winter here. So, if you want a perennial grass, you should choose a different species. Many ornamental and wild grasses have similar seed heads that are perennial just about everywhere. Just don’t plant an invasive species…

Cenchrus setaceus ‘Rubrum’ (Purple Fountain Grass) on 7-13-18, #477-4.

The Purple Fountain Grass is best grown where it will create an interesting focal point and in the back or center of combination planters. They probably aren’t too particular about the soil type as long as it is well-draining. After all, it is a grass…

Cenchrus setaceus ‘Rubrum’ (Purple Fountain Grass) on 7-29-18, #487-28.

The Purple Fountain Grass makes an excellent addition to flower beds but is best placed where they can be seen. I say that because I put a Salvia microphylla ‘Hot Lips’ in this bed which nearly hid the Purple Fountain Grass.

Cenchrus setaceus ‘Rubrum’ (Purple Fountain Grass) on 10-5-18, #516-2.

I haven’t really grown many cultivars of ornamental grasses so this one was a new experience. I am pleased with its performance and will definitely buy more in the future if they are available locally.

I hope you enjoyed this page and maybe found it useful. If you have any comments, questions, or suggestions, I would like to hear from you. Please click on “like” if you visited this page. It helps us bloggers stay motivated. 🙂 You can check out the links below for further reading. The links take you directly to the genus and species of this plant. The links below are to websites that list this plant as a Cenchrus setaceus or Pennisetum setaceum.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
MISSOURI BOTANICAL GARDEN
DAVE’S GARDEN
THE NATIONAL GARDENING ASSOCIATION
NORTH CAROLINA STATE UNIVERSITY
GARDENIA
GARDENING KNOW HOW

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