''Caltha introloba'', commonly known as the alpine marsh-marigold is a small (during flowering 1–2 cm high) hairless,

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 ...

alpine

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

, that is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the alpine regions of Australia and Tasmania.

Description

The alpine marsh-marigold is a small hairless,

alpine

, with short, stout

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 ...

s, and forms dense mats. Its leaves have petioles of about 5 cm long with a leaf blade that is oblong or lanceolate rounded triangular, 8–40 mm long, emarginate, with 2 lanceolate triangular appendages of 4–20 mm long on the upper surface. The flowering stem is 1–2 cm long, but grows to 5–10 cm when seeds are ripe. The five to eight sepals are between 10 and 22 mm long, white, but often tinged pink or purple, particularly at the base and the veins. Fifteen to thirty

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 with white or often pinkish

filament The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * Solar filament ...

s and yellow pollen encircle six to eighteen free carpels. When ripe, these have developed into follicles which are spreading, have short beaks and contain few seeds. Flowering occurs between November and December, often directly from under the receding snow.

Distribution

''Caltha introloba'' is known from Victoria, New South Wales and Tasmania where it grows in alpine fields. It occurs on the slopes of Mt Kosciusko and is locally common in spots with late-lying snow and between moss on the high ranges, such as Baw Baws, Snowy Range, Mt Buffalo, Bogong and Dargo High Plains. Usually flowering at edges of receding snow drifts.

Ecology

''Caltha introloba'' occurs in Victoria with '' Brachyscome tadgellii'', ''

Carex gaudichaudiana ''Carex gaudichaudiana'', also known as fen sedge, is a tussock-forming species of perennial sedge in the family Cyperaceae. It is native to parts of Australia and New Zealand. Description The sedge has a long rhizome with loosely tufted shoots ...

'', '' Carpha nivicola'', '' Drosera arcturi'', '' Oreobolus distichus'' and '' Schoenus calyptratus''. Flower buds start growing in the middle of the southern summer (January) and have fully developed when fresh snow no longer melts away in May. Mostly the flowers open after the October snow melt, and some flowers open under the snow cover if this persists unto mid-November. Seeds usually have completely developed at the end of summer (February). In an experiment, flower formation is triggered by long days and strong light. Another experiment showed that flowers will only open after a cold period, probably a mechanism to prevent premature opening in autumn. Seeds of ''Caltha introloba'' in another experiment were shown to germinate best between 22 and 27 °C, with a delay of 40–60 days, and hardly between 0 and 15 °C. However, after four months at 1–2 °C, germination below 15 °C was much faster and better. Seeds of ''C. introloba'' shed in the summer are thus unlikely to germinate before the snow melts in the following spring. Growth and photosynthesis are best around 15 °C, which is near the mean maximum temperature during summer in the alpine conditions this species is growing. Photosynthesis did also occur at 0 °C and the growing season probably includes the entire period the plants are not covered by snow.

References

External links

plant with flowers
{{Taxonbar, from=Q17812118 introloba Flora of Australia Taxa named by Ferdinand von Mueller