Roscoea is a small genus of late spring/summer growing plants of the ginger family, Zingiberaceae. They have a growing point from which a cluster of thickened roots descend, somewhat like a Dahlia but in miniature form. The leaves are reminiscent of a miniature sweet corn with the flower at the apex. The flower is somewhat orchid like (thinking Masdevallia) with one large descending petal and several smaller petals above and beside the main petal. Species originate mainly from India, Nepal and China.
In Tasmania they need partial to full shade and additional summer watering to grow well. They tolerate moisture when dormant and do equally well in the ground or pots. For those in cooler climates they are said to be outdoors hardy in Britain. In Canberra, Lyn Edwards found they do better in pots for her than in the ground probably because of competition from trees and shrubs for water during hot spells. They are not difficult to grow there where there are long hot dry summers with temperatures in the 30's C (90-92F) and winters down to -9C (16F) as long as they have enough water and protection from the sun.
Seeds should be sown fresh if possible and usually germinate easily. When sown in late summer germination usually occurs in autumn, while seed sown in early spring emerges with the timing of mature plants. Plants in the ground often self-sow. Jack Elliott found that seeds from collecting expeditions, often not very fresh, germinate OK. In such cases, they should be sown as soon as possible and keep the pots outside in the cold through the winter, where they germinate in late spring.
Roscoea was discussed by the Pacific Bulb Society list in February 2003 as the topic of the week. Rob Hamilton and Lyn Edwards introduced the discussion. The information above was taken from the introduction. Click here for the whole Co-Introduction. Another good resource is the online Flora of China
Roscoea alpina flowering January in Tasmania. Photo by Rob Hamilton.
Roscoea auriculata flowering January in Tasmania. Photo by Rob Hamilton.
Roscoea beesiana? Photos of plants flowering during January in Canberra by Lyn Edwards and Paul Tyerman.
Roscoea capitata? flowering December in Tasmania, in reality a rich, deep purple. Photo by Rob Hamilton.
Roscoea cautleyoides Photos 1 was taken by Rob Hamilton of plant flowering during November in Tasmania. Photo 2 was taken by Bob Rutemoeller at Wisley in the UK during May 2005. Photo 3 was taken by Nhu Nguyen at the Royal Botanic Garden at Edinburgh in August 2010.
Four photos added by Mark McDonough. This species is endemic to China, from Sichuan and Yunnan provinces, found growing in pine forests and meadows at 2000-3500 meters. Flower color can vary from yellow to purple, white, or pink. Stems reach 6" - 24" (15 - 60 cm) tall, flowering before or with the leaves, from May - August, depending on the form. My plants are May-June flowering, with a fall rebloom, growing erect to 18" (45 cm) tall, and pure light yellow flowers. Difficult to capture the color well in digital photos, here are a few photos to capture the essence of the plant. Photos taken June 8, 2006.
Roscoea humeana Photos of plants flowering during December in Tasmania by Rob Hamilton, and another taken by Bob Rutemoeller at Kew Gardens (England) in May 2004. The split dorsal petal is unusual.
Roscoea purpurea is native to the Himalayas.
Roscoea purpurea 'Red Gurkha' The photos below were taken by Nhu Nguyen in early August at the Royal Botanic Garden at Edinburgh. It is grown in the ground in a shady spot with only spotted sunlight. In the winter, the area is covered in snow.
Roscoea scillifolia flowering in Canberra. Photo by Paul Tyerman.
