''Roscoea ngainoi'' is a

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

occurring in the Ukhrul district of

Manipur state Manipur () ( mni, Kangleipak) is a state in Northeast India, with the city of Imphal as its capital. It is bounded by the Indian states of Nagaland to the north, Mizoram to the south and Assam to the west. It also borders two regions of Myanm ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

. Most members of the ginger family ( Zingiberaceae), to which it belongs, are tropical, but like other species of ''

Roscoea ''Roscoea'' is a genus of perennial plants of the family (biology), family Zingiberaceae (the ginger family). Most members of the family are tropical, whereas ''Roscoea'' species are native to mountainous regions of the Himalayas, China and its ...

'', ''R. ngainoi'' grows in much colder mountainous regions.

Description

Like all members of the genus ''Roscoea'', ''R. ngainoi'' grows from a short vertical

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

, to which are attached the tuberous roots. These produce "

pseudostem A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrien ...

s": structures which resemble stems but are actually formed from the tightly wrapped bases (sheaths) of leaves. Plants are around tall when in flower with up to six leaves. The first two or three consist only of sheaths; the remaining leaves have a blade long by wide. At the junction of the sheath and blade there is a small

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

, extending to . The flower spike (inflorescence) is held within the leaves with generally one flower emerging at a time on a long corolla tube of up to . The general flower colour is deep purple. The bracts which subtend the flowers are shorter than the

calyx Calyx or calyce (plural "calyces"), from the Latin ''calix'' which itself comes from the Ancient Greek ''κάλυξ'' (''kálux'') meaning "husk" or "pod", may refer to: Biology * Calyx (anatomy), collective name for several cup-like structures ...

. Each flower has the typical structure for ''

'' (see the diagrams in that article). There is a tube-shaped outer

, about long, with a three-lobed apex. Next the three

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s (the corolla) form a tube, longer than the calyx, terminating in three lobes, an upright central lobe, about long by wide, and two somewhat narrower side lobes, long by wide. Inside the petals are structures formed from four sterile

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s (

staminodes In botany, a staminode is an often rudimentary, sterile or abortive stamen, which means that it does not produce pollen.Jackson, Benjamin, Daydon; ''A Glossary of Botanic Terms with their Derivation and Accent''; Published by Gerald Duckworth & C ...

): two lateral staminodes form what appear to be small upright petals, which are by , with a short narrowed part (a "claw") at the base; two central staminodes are partially fused at the base to form a lip or labellum, long by wide. The labellum divides to form two separated lobes, each long at the central edge, shorter at the outer edge. Two or three white lines extend from the base of each lobe, sometimes more than halfway to its finely toothed (serrulate) apex. The single functional stamen has a white

anther The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

, about long, with long spurs, formed from the connective tissue between the two capsules of the anther. The species resembles '' R. tibetica'', but the leaf blades are smaller, the corolla tubes much longer, exceeding the calyx, and the labellum is differently shaped and has white lines at the base. It was found on hills at elevations of , in open grassy areas, where plants such as ''

Lilium mackliniae ''Lilium mackliniae'', the Shirui lily or Shirui Kashung Timrawon, is a rare Indian species of plant found only in the upper reaches of the Shirui hill ranges in the Ukhrul district of Manipur, India, at an elevation of above sea level. It is l ...

'' were also present.

Taxonomy

''R. ngainoi'' was first described by A.A. Mao and M. Bhaumik in a paper published in 2008 (but dated 2007). The specific epithet ''ngainoi'' is derived from the Ngaino peak in

Manipur Manipur () ( mni, Kangleipak) is a state in Northeast India, with the city of Imphal as its capital. It is bounded by the Indian states of Nagaland to the north, Mizoram to the south and Assam to the west. It also borders two regions of Myanm ...

, where the species was first found; the

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was collected in March 2005 at an altitude of . ''R. ngainoi'' resembles '' R. tibetica'' and '' R. auriculata''.

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 Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...

. Species of ''Roscoea'' that have been subjected to molecular phylogenetic analysis divide into two clear groups, a Himalayan clade and a "Chinese" clade (which includes some species from outside China). ''R. nganoi'' was discovered after the analysis by so that its phylogenetic position was unknown. Manipur, where it was found, lies between the main distributions of the two clades.

References

{{Taxonbar, from=Q7367558 ngainoi Flora of Assam (region) Plants described in 2008