''Ceratostigma willmottianum'', Chinese plumbago, is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the family

Plumbaginaceae Plumbaginaceae is a family (biology), family of flowering plants, with a cosmopolitan distribution. The family is sometimes referred to as the leadwort family or the plumbago family. Most species in this family are perennial plant, perennial h ...

that is native to western China and Tibet. It is an ornamental deciduous shrub that grows to 1 metre in height, with pale blue

plumbago ''Plumbago'' is a genus of 23 species of flowering plants in the family Plumbaginaceae, native to warm temperate to tropical regions of the world. Common names include plumbago and leadwort (names which are also shared by the genus '' Ceratostig ...

-like flowers appearing in autumn as the leaves start to turn red.

Description

It is a small shrub that develops a

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

as a perennial organ and reaches heights of up to 2 meters. The small, pointed leaves are densely hairy and are shed every year. There are three to seven flowers in an

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

. The

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

flowers have five petals. The five petals are fused together in a tube. The corolla tube is purple and the corolla lobes are bright blue. Capsule fruits measuring around 6 mm with black seeds are formed.

Distribution

This species is native to

East Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...

and the

Himalayas The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...

(Chinese provinces:

Gansu Gansu is a provinces of China, province in Northwestern China. Its capital and largest city is Lanzhou, in the southeastern part of the province. The seventh-largest administrative district by area at , Gansu lies between the Tibetan Plateau, Ti ...

, western

Guizhou ) , image_skyline = , image_caption = , image_map = Guizhou in China (+all claims hatched).svg , mapsize = 275px , map_alt = Map showing the location of Guizhou Province , map_caption = Map s ...

, southern and western

Sichuan Sichuan is a province in Southwestern China, occupying the Sichuan Basin and Tibetan Plateau—between the Jinsha River to the west, the Daba Mountains to the north, and the Yunnan–Guizhou Plateau to the south. Its capital city is Cheng ...

, southeastern

Xizang The Tibet Autonomous Region (TAR), often shortened to Tibet in English or Xizang in Hanyu Pinyin, is an autonomous region of the People's Republic of China. It was established in 1965 to replace the Tibet Area, a former administrative divisio ...

, eastern and northern

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

). It grows in warm valleys at altitudes between 700 and 3500 m above sea level.

Etymology

''Ceratostigma'' is derived from

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

, meaning 'horned stigma'. This is in reference to the 'shape of the stigmatic surface'.Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 99, 407 The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''willmottianum'' was named for Miss

Ellen Ann Willmott Ellen Ann Willmott (19 August 1858 – 27 September 1934) was an English horticulturist. She was an influential member of the Royal Horticultural Society, and a recipient of the first Victoria Medal of Honour, awarded to British horticulturists ...

(1858-1934), a keen gardener and plant introducer from

Warley Place Warley Place is a nature reserve south of Brentwood in Great Warley, Essex. It is managed by the Essex Wildlife Trust and the former garden structures are Grade II listed. The now demolished house was home to renowned horticulturalist Ellen Wil ...

, Essex, UK.

Cultivation

''Ceratostigma willmottianum'' is cultivated as a garden plant, valued for its late season red leaves and rich blue flowers. Both the species and the

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

('Lice') have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

. There is also a cultivar with yellow foliage, ('Palmgold').

References

willmottianum Flora of China Flora of Tibet {{Caryophyllales-stub