Roscoea purpurea (Roscoe's Lily or Purple Roscoe)


Botanical Information

FamilyZingiberaceae
GenusRoscoea
Speciespurpurea
CategoryBulbs, Perennials, Tropicals
ReferencesBranney, T.M.E. (2009). Hedychium, Roscoea and Zingiber. London: RHS.
OriginFrom the Himalayas and first collected by Francis Buchanan in Nepal the genus Roscoea was named in 1806 by the English botanist James E. Smith in honour of his friend William Roscoe the founder of the botanical garden in Liverpool, England. There are between, depending on source, some 18-22 species and based on recent phylogenetic analysis can be placed into two distinct groups; the Himalayan and Chinese.

Details

USDA Hardiness Zone6
USDA Hardiness Ref.
Canadian Hardiness Zone5a - 6a
Canada Hardiness Ref.
RHS Hardiness ZoneH6 - H7
RHS Hardiness Ref.
Temperature (°C)-23 -(-18)
Temperature (°F)-10 - 0
Height20 - 30 cm
GrowthMedium
Flowering PeriodMay, June, July, August, September

Description and Growing Information

General DescriptionGrowth originates from a pseudo stem and rhizomatous fleshy roots.
PropagationEasy to germinate from seed the plants flower 2-3 years later. Division of mature clumps with care taken not to break or otherwise bruise the fleshy roots which can become entangled in mature clumps.
CultivationMost species are considered hardy to USDA Zone 6 although not all species and cultivars have been proven so. Plant in a moist but well drained soil in partial to three quarters sun; full sun can lead to leaf scorch. Scree, rock gardens and pots are suitable placements. I overwinter plants in a dormant state in a cool room and force into bloom in the spring. After plants have bloomed, decrease watering towards the end of summer by laying the pot on its side in a cool greenhouse or cold frame. Once the foliage dies back, carefully remove it and store the potted, dormant plants in a cool, dry location until spring.
HabitatPlants generally require a relatively sunny position with moisture-retaining but well-drained soil.
Flower DescriptionThe flowers have three outside petals ( the top one called the hood) and 4 staminoides with the lower two usually fused together forming the labellum. The bloom has a long floral tube which appears adapted to pollination by long-tongued insects.The flower colour is variable according to regional locations, ranging from lavender, purple-lilac, white, pink and red.
Fruit DescriptionThe fruit is a capsule with arilate seeds, which are black in colour.

Photographs