Physostegia virginiana (obedient plant or false dragonhead) is a species of flowering plant in the family Lamiaceae, native to most of the United States, except for the Pacific Coast states.^[1]

Description

It is an erect herbaceous perennial growing to 1.2 m (4 ft) tall by 60 cm (24 in) broad, with pink, purple or white racemes of tubular flowers in summer.^[2] The flowers are on swivels that can be bent right or left on the stem, giving rise to the common name. Plants spread by means of rhizomes forming large colonies, especially in moisture-retentive soils.

Flowers

Subspecies

There are two recognized subspecies: P. virginiana ssp. praemorsa (Shinners) Cantino and P. virginiana ssp. virginiana (L.) Benth.

Cultivation

The plant grows in most soils in sun or partial shade, but may become invasive. Therefore frequent division in fall or spring may become necessary.

Cultivars

^[3] (those marked agm have gained the Royal Horticultural Society's Award of Garden Merit)

• 'Alba' - white flowers.
• 'Crown of Snow' - white flowers
• 'Pink Bouquet' - rose pink flowers
• 'Rosea' - pink flowers
• 'Rosy Spire' - lavender-pink flowers
• 'Summer Snow'agm^[4] - pure white flowers
• 'Variegata' - pink flowers, leaves green variegated with white
• 'Vivid'agm^[5] - bright pink flowers

References

1. ^ "Physostegia virginiana". USDA PLANTS. http://plants.usda.gov/java/profile?symbol=PHVI8.
2. ^ RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. pp. 1136. ISBN 1405332964.
3. ^ Michigan State University Extension: Physostegia virginiana
4. ^ http://apps.rhs.org.uk/plantselector/plant?plantid=1458
5. ^ http://apps.rhs.org.uk/plantselector/plant?plantid=1458