''Pterostylis cardiostigma'' is a species of

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

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 ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. It has erect leaves, the upper leaves higher than the flower which is stiff, upright and green with narrow white stripes and pinkish tips. It barely opens fully and is sometimes mistaken for an unopened flower of '' Pterostylis banksii'' with which it often grows.

Description

''Pterostylis cardiostigma'' is a terrestrial,

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 ...

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

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 ...

with a large, heart-shaped underground

tuber Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing ...

. There are between four and seven upright leaves on the flowering stem, the uppermost leaf higher than the flower. The leaves are erect, linear to lance-shaped, long and wide, with a prominent red keel. The flower is green with fine white stripes and pink or red tips and is borne on a flowering stem tall. The dorsal

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

and

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 are fused, forming a narrow hood or "galea" over the

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...

and the dorsal sepal is longer than the petals. The lower half of the galea is vertical, the upper part curves forward, but never as far as the horizontal. The lateral sepals are more or less erect, much higher than the galea and have long, narrow, red, thread-like tips. The labellum is curved, red and pointed. Although it can only be seen by opening the flower, the stigma has a characteristic heart shape. Flowering occurs from October to December.

Taxonomy and naming

''Pterostylis cardiostigma'' was first formally described in 1983 by Dorothy Cooper and the description was published in '' New Zealand Journal of Botany'' from a specimen she collected at

Days Bay Days Bay is a residential area in Lower Hutt in the Wellington Region of the North Island of New Zealand. It is walled on three sides by steep bush-clad slopes. Most of its level land is occupied by Williams Park and an independent boys' prima ...

. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''cardiostigma'') is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

words ''kardia'' meaning "heart" and ''stigma'' meaning the part of the flower that receives pollen.

Distribution and habitat

This greenhood grows in scrub and forest on both the

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

s of New Zealand. It is often found with ''P. banksii''.

Ecology

The flowers of ''P. cardiostigma'' are very narrow and often appear not to be fully open. Early in the development of the flower, the labellum protrudes, suggesting that pollination can take place. However, the stigma is larger than in other ''Pterostylis'' and pollinia often fall onto it so that

self-pollination Self-pollination is a form of pollination in which pollen from the same plant arrives at the Stigma (botany), stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen i ...

also occurs.

References

{{Taxonbar, from=Q15492040 cardiostigma Orchids of New Zealand Plants described in 1983