Roscoea kunmingensis
Encyclopedia
Roscoea kunmingensis is a perennial herbaceous plant
native to the mountains of China
, being found in Yunnan
. Most members of the ginger family (Zingiberaceae
), to which it belongs, are tropical, but R. kunmingensis, like other species of Roscoea
, grows in much colder mountainous regions.
native to mountains in Yunnan
, China
. where it is found in forests, at heights of 2,100–2,200 m.
Like all members of the genus Roscoea, it dies back each year to a short vertical rhizome
, to which are attached the tuberous roots
. When growth begins again, "pseudostems" are produced: structures which resemble stems but are actually formed from the tightly wrapped bases (sheaths) of its leaves. R. kunmingensis is one of the smaller members of the genus; plants are 8–12 cm tall, with about four leaves consisting only of a sheath and futher leaves with blades 8–20 cm long by 2.3–3 cm wide (rarely to 4.2 cm wide). The blade is smooth (glabrous). There is a small ligule, extending to about 3 mm, at the junction of the leaf sheath and blade.
In its native habitats, R. kunmingensis flowers between May and June. The stem (peduncle
) of the flower spike (inflorescence
) is hidden by the leaf sheaths. The spike has bracts, between 0.5 cm and 3.5 cm in length, which in some forms may enlarge to up to 8 cm after flowering. There are only one or two flowers per spike.
Each flower has the typical structure for Roscoea
(see the diagrams in that article). There is a tube-shaped outer calyx. Next the three petal
s (the corolla) form a tube which is 3.5–4 cm and terminates in three lobes, an oblong upright central lobe, about 1.5–2 cm long by 6–8 mm wide, and two side lobes, narrower than the central lobe. Inside the petals are structures formed from four sterile stamen
s (staminodes): two lateral staminodes form what appear to be upright petals, about 1.4 cm long; two central staminodes are fused to form a lip or labellum, about 1.6–2.1 cm by 1–1.5 cm, which is deeply divided at the end into two lobes. The labellum has white lines at its base. The form in cultivation has purple flowers.
The single functional stamen has an anther about 4 mm long, with about 3 mm long spurs formed from the connective tissue between the two capsules of the anther. The cylinder-shaped ovary is about 3–3.5 cm long.
area of Yunnan. R. kunmingensis is closely related to R. praecox
.
Two varieties have been distinguished.
.
Species of Roscoea divide into two clear groups, a Himalayan clade and a "Chinese" clade (which includes some species from outside China). The two clades correspond to a geographical separation, being divided by the Brahmaputra River
as it flows south at the end of the Himalayan mountain chain. It has been suggested that the genus may have originated in this area and then spread westwards along the Himalayas and eastwards into the mountains of China and its southern neighbours.
R. kunmingensis was not included in the analysis by Ngamriabsakul et al. It occurs in the geographical region of the Chinese clade.
and was described as thriving "in a fertile loam, outside, over many years, including our all time low of −17 °C in the winter of 2010-2011."
For propagation, see Roscoea: Cultivation.
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
native to the mountains of China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, being found in Yunnan
Yunnan
Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...
. Most members of the ginger family (Zingiberaceae
Zingiberaceae
Zingiberaceae, or the Ginger family, is a family of flowering plants consisting of aromatic perennial herbs with creeping horizontal or tuberous rhizomes, comprising ca. 52 genera and more than 1300 species, distributed throughout tropical Africa, Asia, and the Americas.Many species are important...
), to which it belongs, are tropical, but R. kunmingensis, like other species of Roscoea
Roscoea
Roscoea is a genus of perennial plants of the family Zingiberaceae . Most members of the family are tropical, whereas Roscoea species are native to mountainous regions of the Himalayas, China and its southern neighbours. Roscoea flowers superficially resemble orchids, although they are not related...
, grows in much colder mountainous regions.
Description
Roscoea kunmingensis is a perennial herbaceous plantHerbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
native to mountains in Yunnan
Yunnan
Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. where it is found in forests, at heights of 2,100–2,200 m.
Like all members of the genus Roscoea, it dies back each year to a short vertical rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
, to which are attached the tuberous roots
Tuber
Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...
. When growth begins again, "pseudostems" are produced: structures which resemble stems but are actually formed from the tightly wrapped bases (sheaths) of its leaves. R. kunmingensis is one of the smaller members of the genus; plants are 8–12 cm tall, with about four leaves consisting only of a sheath and futher leaves with blades 8–20 cm long by 2.3–3 cm wide (rarely to 4.2 cm wide). The blade is smooth (glabrous). There is a small ligule, extending to about 3 mm, at the junction of the leaf sheath and blade.
In its native habitats, R. kunmingensis flowers between May and June. The stem (peduncle
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
) of the flower spike (inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
) is hidden by the leaf sheaths. The spike has bracts, between 0.5 cm and 3.5 cm in length, which in some forms may enlarge to up to 8 cm after flowering. There are only one or two flowers per spike.
Each flower has the typical structure for Roscoea
Roscoea
Roscoea is a genus of perennial plants of the family Zingiberaceae . Most members of the family are tropical, whereas Roscoea species are native to mountainous regions of the Himalayas, China and its southern neighbours. Roscoea flowers superficially resemble orchids, although they are not related...
(see the diagrams in that article). There is a tube-shaped outer calyx. Next the three petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s (the corolla) form a tube which is 3.5–4 cm and terminates in three lobes, an oblong upright central lobe, about 1.5–2 cm long by 6–8 mm wide, and two side lobes, narrower than the central lobe. Inside the petals are structures formed from four sterile stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s (staminodes): two lateral staminodes form what appear to be upright petals, about 1.4 cm long; two central staminodes are fused to form a lip or labellum, about 1.6–2.1 cm by 1–1.5 cm, which is deeply divided at the end into two lobes. The labellum has white lines at its base. The form in cultivation has purple flowers.
The single functional stamen has an anther about 4 mm long, with about 3 mm long spurs formed from the connective tissue between the two capsules of the anther. The cylinder-shaped ovary is about 3–3.5 cm long.
Taxonomy
Roscoea kunmingensis was first described scientifically in 1992 by Tong Shao Quan, a Chinese botanist. The specific epithet refers to the locality of the plant, in the KunmingKunming
' is the capital and largest city of Yunnan Province in Southwest China. It was known as Yunnan-Fou until the 1920s. A prefecture-level city, it is the political, economic, communications and cultural centre of Yunnan, and is the seat of the provincial government...
area of Yunnan. R. kunmingensis is closely related to R. praecox
Roscoea praecox
Roscoea praecox is a perennial herbaceous plant occurring in the Yunnan province of China. Most members of the ginger family , to which it belongs, are tropical, but R. praecox, like other species of Roscoea, grows in much colder mountainous regions...
.
Two varieties have been distinguished.
- R. kunmingensis var. kunmingensis has narrower leaf blades (to 3 cm wide) and bracts between 0.5 and 0.7 cm long.
- R. kunmingensis var. elongatobractea has wider leaf blades (to 4.2 cm wide) and bracts between 2.5 and 3.5 cm long, lengthening after flowering to as much as 8 cm.
Evolution and phylogeny
The Zingiberaceae family is mainly tropical in distribution. The unusual mountainous distribution of Roscoea may have evolved relatively recently and be a response to the uplift taking place in the region in the last 50 million years or so due to the collision of the Indian and Asian tectonic platesPlate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
.
Species of Roscoea divide into two clear groups, a Himalayan clade and a "Chinese" clade (which includes some species from outside China). The two clades correspond to a geographical separation, being divided by the Brahmaputra River
Brahmaputra River
The Brahmaputra , also called Tsangpo-Brahmaputra, is a trans-boundary river and one of the major rivers of Asia. It is the only Indian river that is attributed the masculine gender and thus referred to as a in Indo-Aryan languages and languages with Indo-Aryan influence...
as it flows south at the end of the Himalayan mountain chain. It has been suggested that the genus may have originated in this area and then spread westwards along the Himalayas and eastwards into the mountains of China and its southern neighbours.
R. kunmingensis was not included in the analysis by Ngamriabsakul et al. It occurs in the geographical region of the Chinese clade.
Cultivation
Some Roscoea species and cultivars are grown in rock gardens. They generally require a relatively sunny position with moisture-retaining but well-drained soil. As they do not appear above ground until late spring or even early summer, they escape frost damage in regions where subzero temperatures occur. R. kunmingensis has been offered for sale in the United KingdomUnited Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and was described as thriving "in a fertile loam, outside, over many years, including our all time low of −17 °C in the winter of 2010-2011."
For propagation, see Roscoea: Cultivation.