Peppermint

Mentha x piperita L.

A cross between the native Mentha aquatica and introduced Mentha spicata (Spearmint)

Order - Lamiales

Family - Lamiaceae

Names:

Mentha

Piperita

Peppermint

Other Names:

Eau de Cologne Mint.

Summary:

A strongly aromatic, almost hairless, perennial herb with purple flowers and opposite, toothed leaves.

Description:

Cotyledons:

Two.

Leaves:

Opposite

Stipules -

Petiole - 3-18 mm long.

Blade - Lance shaped, 15-80 mm long by 10-37 mm wide, toothed edges, pointed tip, aromatic. Hairless or almost so or slightly rough to touch. Glandular aromatic. Tapered base.

Stems:

Erect, 500-1000 mm tall, aromatic. Hairless or almost so.

Flower head:

Short, broad, terminal spike, 20-30 mm long by 12-16 mm diameter with many flowers.

Floral leaves reduced to bracts.

Flowers:

Strongly aromatic.

On stalks(pedicels) 2-3 mm long.

Ovary -

Calyx - Bell shaped, tubular, cylindrical, 3-5 mm long, 10-12 ribbed, smooth and hairless except on the teeth. Tube 2-3 mm long, lobes, triangular and similar sized, 1-1.5 mm long, smooth or slightly rough to touch. Conspicuous oil glands.

Petals - Purple, sometimes spotted, 5-6.5 mm long, smooth, oblong lobes with rounded tips.

Stamens - Inside the flower. Filaments 1-1.5 mm long.

Anthers - 0.5 mm long.

Fruit:

Pale brown, smooth nutlet.

Seeds:

Small.

Roots:

Rhizomes.

Key Characters:

Glabrous herb with occasionally a few scattered short hairs, especially along the stems.

Leaves stalked or petiolate.

Inflorescence of false whorls forming cylindrical spikes.

Whorls many flowered.

Floral leaves reduced to narrow bracts.

Calyx 3-5 mm long.

From J.M. Black and Judy Wheeler.

Biology:

Life cycle:

Perennial

Physiology:

Reproduction:

By rhizomes.

Flowering times:

Summer in SA.

March in Perth.

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by rhizomes.

Origin and History:

Europe.

Introduced as a crop plant.

Distribution:

ACT, NSW, SA, TAS, VIC.

Habitats:

Climate:

Cool temperate. High rainfall areas around 400 latitude.

Soil:

Prefers wet areas.

Plant Associations:

Significance:

Beneficial:

Used for food and oils.

Oil extracted from leaves by steam distillation and used for flavouring confectionery, pharmaceutical products and foods.

Detrimental:

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

Thresholds:

Eradication strategies:

Herbicide resistance:

Biological Control:

Related plants:

Apple Mint (Mentha X rotundifolia)

Eau-de-Cologne Mint (Mentha X piperita var. citrata)

Native Pennyroyal (Mentha satureioides)

Peppermint (Mentha X piperita)

Pennyroyal (Mentha pulegium)

River Mint (Mentha australis)

Slender Mint (Mentha diemenica)

Spearmint (Mentha spicata)

Mentha aquatica

Mentha suaveolens

Plants of similar appearance:

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P732.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne).

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P563.

Reid, R.L. (1990) The Manual of Australian Agriculture. (Butterworths, Sydney). P114.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.