Roscoea bhutanica

Last updated

Roscoea bhutanica
Roscoea bhutanica.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Zingiberales
Family: Zingiberaceae
Genus: Roscoea
Species:
R. bhutanica
Binomial name
Roscoea bhutanica
Ngamr. [1]

Roscoea bhutanica is a perennial herbaceous plant native to the mountains of Bhutan and Tibet. Formerly regarded as part of Roscoea tibetica , it was recognized as a separate species in 2000. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. bhutanica, like other species of Roscoea , grows in much colder mountainous regions. [2]

Contents

Description

Roscoea bhutanica is a perennial herbaceous plant. 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. [3] R. bhutanica is one of the smaller members of the genus; plants are 8–14 cm tall, with around four to eight or more leaves, the first two to four being bladeless, the others with smooth (glabrous) blades 4–21 cm long by 1–1.6 cm wide. The leaves are clustered together at the base. [2]

The stem (peduncle) of the flower spike is hidden by the leaf sheaths. Bracts some 4.5–8 cm long by 1–1.6  wide enclose the flowers, which are purple and appear one at a time, just above the leaves. [2]

Each flower has the typical structure for Roscoea (see the diagrams in that article). There is a tube-shaped outer calyx, 5–6.5 cm long with a two-toothed apex. Next the three petals (the corolla) form a tube which is usually about 1 cm longer than the calyx at 5–6.5 cm and terminates in three lobes, a narrow upright central lobe, about 2.3–2.6 cm long and 1.1–1.3 cm wide, and two narrower side lobes, each 2.4–2.8 cm long by 4–6 mm wide. Inside the petals are structures formed from four sterile stamens (staminodes): two lateral staminodes form what appear to be narrow upright petals, 1.6–1.9 cm long; two central staminodes are fused to form a lip or labellum, about 2.5–3.2 cm by 1.6–2 cm, which is slightly bent downwards and divided into two lobes for less than half its length. [2] [3]

The single functional stamen has a white anther, about 6–7 mm long, above pointed spurs formed from the connective tissue between the two capsules of the anther. The style is pinkish-white with a white stigma. The ovary is about 1–1.7 cm long. [2]

Taxonomy

Roscoea bhutanica was first described scientifically in 2000 in a paper which gives the author of the binomial name as Chatchai Ngamriabsakul, a Thai botanist. The specific epithet bhutanica refers to the main area of distribution of the species, namely Bhutan. [2]

As explained further below, the species was originally considered to be part of R. tibetica .

Evolution and phylogeny

The family Zingiberaceae 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 plates. [4]

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, their main distributions 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. [4]

R. tibetica was formerly thought to be unique in occurring on both sides of the south-flowing section of the Brahmaputra River. However, genetic analysis in 2000 showed that plants to the west, in Bhutan, were distinct from those to the east, in China. The former were placed in a new species, R. bhutanica. R. bhutanica falls into the Himalayan clade whereas R. tibetica belongs to the Chinese clade, as would be expected from their respective distributions. [2]

The two species are superficially similar, in that they are both small and have a tight group of basal leaves. Young plants of the two species are not easily distinguished, but later it can be seen that R. tibetica retains a rosette of leaves, whereas R. bhutanica develops leaves in two opposite rows. [2]

Distribution and habitat

Roscoea bhutanica is native to mountains in Bhutan and southern Tibet. It has been found at altitudes of between 2,100 and 3,500 metres, in wooded valleys and forest clearings. [2]

Related Research Articles

<i>Roscoea</i> Genus of flowering plants

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. The flowers of Roscoea have a complicated structure, in which some of the showy coloured parts are not formed by petals, but by staminodes, sterile stamens which have evolved to become like petals. Some species are grown as ornamental plants in gardens.

<i>Roscoea auriculata</i> Species of plant

Roscoea auriculata is a perennial herbaceous plant occurring in the eastern Himalayas, in Tibet, Bhutan, Nepal and Sikkim. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. auriculata, like other species of Roscoea, grows in much colder mountainous regions. It is sometimes grown as an ornamental plant in gardens.

<i>Roscoea humeana</i> Species of plant

Roscoea humeana is a species of flowering plant in the Zingiberaceae family. It is a perennial occurring in the Sichuan and Yunnan provinces of China. Most members of the ginger family, to which it belongs, are tropical, but R. humeana, like other species of Roscoea, grows in much colder mountainous regions. It is sometimes grown as an ornamental plant in gardens.

<i>Roscoea alpina</i> Species of plant

Roscoea alpina is a perennial herbaceous plant native to the Himalayas. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. alpina, like other species of Roscoea, grows in much colder mountainous regions. It is sometimes grown as an ornamental plant in gardens.

<i>Roscoea tibetica</i> Species of flowering plant

Roscoea tibetica is a perennial herbaceous plant native to the mountains of China, being found in Tibet, Sichuan and Yunnan. The species formerly included plants found in Bhutan; in 2000, these were separated into a new species, Roscoea bhutanica. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. tibetica, like other species of Roscoea, grows in much colder mountainous regions. R. tibetica is sometimes grown as an ornamental plant in gardens. In 2020, it was proposed that R. tibetica be split again.

<i>Roscoea kunmingensis</i> Species of flowering plant

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.

<i>Roscoea capitata</i> Species of flowering plant

Roscoea capitata is a perennial herbaceous plant native to the Himalayas, being found in Nepal. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. capitata, like other species of Roscoea, grows in much colder mountainous regions.

<i>Roscoea forrestii</i> Species of flowering plant

Roscoea forrestii is a perennial herbaceous plant occurring in the Sichuan and Yunnan provinces of China. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. forrestii, like other species of Roscoea, grows in much colder mountainous regions. It is sometimes grown as an ornamental plant in gardens. It was named after George Forrest (1873–1932) who discovered it in Yunnan.

<i>Roscoea tumjensis</i> Species of flowering plant

Roscoea tumjensis is a perennial herbaceous plant occurring in the Himalayas, in Nepal. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. tumjensis, like other species of Roscoea, grows in much colder mountainous regions.

Roscoea cangshanensis 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. canshanensis, like other species of Roscoea, grows in much colder mountainous regions.

<i>Roscoea praecox</i> Species of flowering plant

Roscoea praecox is a perennial herbaceous plant occurring in the Yunnan province of China. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. praecox, like other species of Roscoea, grows in much colder mountainous regions. It is sometimes grown as an ornamental plant in gardens.

<i>Roscoea australis</i> Species of flowering plant

Roscoea australis is a perennial herbaceous plant found in Burma, to the south of all other members of the genus. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. australis, like other species of Roscoea, grows in much colder mountainous regions.

Roscoea brandisii is a species of herbaceous flowering plant in the Zingiberaceae family. It is a perennial found in the state of Meghalaya, India. Most members of the ginger family, to which it belongs, are tropical, but R. brandisii, like other species of Roscoea, grows in much colder mountainous regions.

<i>Roscoea nepalensis</i> Species of flowering plant

Roscoea nepalensis is a perennial herbaceous plant found in Nepal. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. nepalensis, like other species of Roscoea, grows in much colder mountainous regions.

<i>Roscoea debilis</i> Species of flowering plant

Roscoea debilis is a perennial herbaceous plant found in Yunnan, China. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. debilis, like other species of Roscoea, grows in much colder mountainous regions.

<i>Roscoea schneideriana</i> Species of flowering plant

Roscoea schneideriana is a perennial herbaceous plant found in China, in Tibet, Sichuan and Yunnan. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but R. schneideriana, like other species of Roscoea, grows in much colder mountainous regions.

Roscoea ngainoi is a perennial herbaceous plant occurring in the Ukhrul district of Manipur state, India. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but like other species of Roscoea, R. ngainoi grows in much colder mountainous regions.

Roscoea ganeshensis is a perennial herbaceous plant occurring in Ganesh Himal in central Nepal. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but like other species of Roscoea, R. ganeshensis grows in much colder mountainous regions. It is used as an ornamental garden plant, requiring moisture and shade in the summer.

<i>Roscoea wardii</i> Species of flowering plant

Roscoea wardii is a perennial herbaceous plant occurring from eastern Arunachal Pradesh in India to western Yunnan in China. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but like other species of Roscoea, R. wardii grows in much colder mountainous regions.

<i>Roscoea scillifolia</i> Species of flowering plant

Roscoea scillifolia is a perennial herbaceous plant occurring in Yunnan in China. Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but like other species of Roscoea, R. scillifolia grows in much colder mountainous regions. As of 2013, the species is only known in cultivation and may be extinct in the wild.

References

  1. ↑ WCSP (2011), World Checklist of Selected Plant Families, The Board of Trustees of the Royal Botanic Gardens, Kew , retrieved 2011-10-03, search for "Roscoea bhutanica"
  2. 1 2 3 4 5 6 7 8 9 Ngamriabsakul, C. & Newman, M.F. (2000), "A New Species of Roscoea Sm. (Zingiberaceae) from Bhutan and Southern Tibet" (PDF), Edinburgh Journal of Botany, 57 (2): 271–278, doi:10.1017/s0960428600000202, archived from the original (PDF) on 2012-06-12, retrieved 2011-10-04
  3. 1 2 Wu, Delin & Larsen, Kai (2000), "Roscoea", in Wu, Zhengyi; Raven, Peter H. & Hong, Deyuan (eds.), Flora of China Vol. 24, Beijing; St. Louis: Science Press; Missouri Botanical Garden, retrieved 2011-10-04
  4. 1 2 Ngamriabsakul, C.; Newman, M.F. & Cronk, Q.C.B. (2000), "Phylogeny and disjunction in Roscoea (Zingiberaceae )" (PDF), Edinburgh Journal of Botany, 57 (1): 39–61, doi:10.1017/s0960428600000032 , retrieved 2011-10-03
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.