Pennisetum clandestinum

Why are the seeds of this species difficult? Some species of the Poaceae family can produce a high proportion of empty seeds, which collectors and curators must take account of. The seeds may have physiological dormancy, which can be overcome with a pre-chill treatment.

Pennisetum clandestinum (Image: S. Wood, RBG Kew)

Seed Storage

This species most probably has Orthodox seeds (based on other species in the same genus) - dry to 15-20% eRH and store at -20ºC, or as cool as possible.

Germination Requirements

Germinate on agar, germination paper or sand, under alternating temperature regimes of 35/20ºC or 30/20ºC (with an 8/16hr photoperiod). Perform a cut-test on any seeds that have not germinated, to check for empty seeds. All empty seeds are non-viable in germination tests.

The seeds of this species may be Physiologically Dormant (based on other species in the same genus). If germination is low, use a moist pre-chill treatment before germinating the seeds at their optimum temperature.

Seed Morphology

Pennisetum clandestinum
(Image: S. Wood, RBG Kew)

The occurrence of empty seeds is common in wild-collected accessions of some Poaceae species. Empty seeds may have a normal seed coat but an absent or under-developed embryo, or limited storage tissue.

The seed (2.5 mm x 1.5 mm) is a caryopsis. The seed is oval in shape, pointed with a persistent short style.

The seeds are dark brown at maturity.

Taxonomy

Family: POACEAE

Accepted name: Pennisetum clandestinum Hochst. ex Chiov.

Synonyms: Pennisetum inclusum Pilg.

Common name: kikuyu grass

References and Links

Black, M., Bewley, J.D. and Halmer, P. (2006). The Encyclopaedia of Seeds: science, technology and uses. CAB International, UK.
Food and Agriculture Organization of the United Nations and International Plant Genetic Resources Institute (1994). Genebank Standards. FAO/IPGRI, Rome, Italy.
International Seed Testing Association (2010). International Rules for Seed Testing: edition 2010. ISTA, Bassersdorf, Switzerland.

AFPD (African Flowering Plants Database) - Conservatoire et Jardin Botaniques de la Ville de Genève, Switzerland, and South African National Biodiversity Institute, Pretoria, RSA: Pennisetum clandestinum.
PROTAbase (Plant Resources of Tropical Africa) - Wageningen, Netherlands: Pennisetum clandestinum.
SID (Seed Information Database) - Royal Botanic Gardens, Kew, UK: Pennisetum clandestinum.
Tropical Forages - CSIRO, DPI&F(Qld), CIAT and ILRI, Brisbane, Australia: Pennisetum clandestinum.
Tropicos - Missouri Botanical Garden, USA: Pennisetum clandestinum.