''Paeonia ludlowii'', is a medium high, deciduous shrub, belonging to the
peonies
The peony or paeony is a flowering plant in the genus ''Paeonia'' , the only genus in the family Paeoniaceae . Peonies are native to Asia, Europe and Western North America. Scientists differ on the number of species that can be distinguished, ...
, 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
southeast Tibet. In Tibet it is known as lumaidao meaning "God’s flower". The vernacular name in Chinese is 大花黄牡丹 (da hua huang mu dan) meaning "big yellow-flowered peony". In English it is sometimes called Tibetan tree peony or Ludlow's tree peony. It has pure yellow, slightly nodding, bowl-shaped flowers, and large, twice compounded, light green leaves.
Description
''P. ludlowii'' is a hairless, deciduous shrub of 2-3½ m high. It has ten chromosomes (2n=10).
Stems and leaves
![Paeonia ludlowii bases of woody stems](https://upload.wikimedia.org/wikipedia/commons/4/49/Paeonia_ludlowii_bases_of_woody_stems.jpg)
The roots get narrower further down and are not fused together. There are no creeping stems (or stolons). The grey to light brown stems grow in clumps (or caespitose), do not branch often, remain approximately the same width during the growing season, and after some years may reach 4 cm in diameter. Young stems are light green, with at their base eight to twelve scales. Leaves are light green above and
glaucous
''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), g ...
pale green below. In the lowest leaves, the
leaf stalk
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in so ...
is 9–15 cm long, while the
leaf blade
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
is twice compounded or deeply divided (or
biternate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...
), with the primary leaflets on a short stem of 2–3 cm, the leaflet blades 6-12 × 5–13 cm, those usually incised almost to the base, having three segments, at base extending along the stalk until disappearing (or
decurrent
''Decurrent'' (sometimes decurring) is a term used in botany and mycology to describe plant or fungal parts that extend downward.
In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petio ...
). Each of the segments 4-9 × 1½-4 cm, mostly incised to midlength into three lobes of 2-5 × ½-1½ cm, with an entire margin or one or two teeth, pointy at their tips.
Inflorescence
![Paeonia ludlowii inflorescence](https://upload.wikimedia.org/wikipedia/commons/e/e2/Paeonia_ludlowii_inflorescence.jpg)
The slightly nodding bisexual flowers grow with three to four on each shoot, extending from the axil of the leaves, they are 10–12 cm wide and sit on a
flower stalk of 5–9 cm long, and open late May and early June. Each flower is subtended by four or five
lance-shaped bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...
s. There are three to five green sepals with a rounded outline of 1½-2½ cm, which have a rounded tip that suddenly narrows into a point. The pure yellow, inverted egg-shaped
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 spreading but slightly curved inwards, 5-5½ × 2½-3½ cm and have a rounded tip. The numerous
filaments are yellow, 1-1½ cm long, topped by yellow
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 ...
s of about 4 mm long. The yellow
disk
Disk or disc may refer to:
* Disk (mathematics), a geometric shape
* Disk storage
Music
* Disc (band), an American experimental music band
* ''Disk'' (album), a 1995 EP by Moby
Other uses
* Disk (functional analysis), a subset of a vector sp ...
at the base of the carpels is ring-shaped, carries teeth, and about 1 mm high. At the centre of each flower are one or two carpels that are topped by yellow stigmas.
Fruit and seed
The carpels develop into cylindrical fruits (or
follicles) of 4¾-7 × 2-3⅓ cm. These contain eventually dark brown, globose seeds of 1⅓ cm in August.
Differences from related species
''
Paeonia delavayi
''Paeonia delavayi'' is a low woody shrub belonging to the peonies, that is endemic to China. The vernacular name in China is 滇牡丹 (diān mǔdan). In English it is called Delavay's tree peony, Delavay peony, Dian peony, and dian mu dan. It ...
'' is closely related to ''P. ludlowii'', but can easily be distinguished because it reproduces mainly by stolons, has fused roots, stems emerge from the ground individually, is only up to 1¾ m high, has segmented leaves with narrow and acute segments. Petals, stamens, disk, and stigmas may be yellow, maroon, orange or white. It has two to eight carpels, which develop in small follicles (2-3½ × 1-1½ cm) and rarely produce seeds. ''P. ludlowii'' on the other hand can only reproduce by seed and lacks creeping underground stems, has slender, regular roots, while the stems form a clump, grows to 2-3½ m high, has leaves with short and suddenly pointed lobes, petals, stamens, disk and stigmas are always yellow, only one or very rarely two carpels develop but this grows into a much larger follicle (4¾-7 × 2-3⅓ cm) which always develops seeds.
Other species of tree peony do not have yellow flowers, do not grow as large and generally have darker green foliage and darker brown bark. Some of the many cultivated cross-breeds of tree peonies may have yellow flowers, but these are not nodding, generally much larger, mostly double flowered, with darker green leaves and much lower.
Taxonomy
In 1886 ''P. delavayi'' with
maroon
Maroon ( US/ UK , Australia ) is a brownish crimson color that takes its name from the French word ''marron'', or chestnut. "Marron" is also one of the French translations for "brown".
According to multiple dictionaries, there are var ...
-red and ''P. lutea'' with yellow flowers, both from Northwest
Yunnan
Yunnan , () is a landlocked Provinces of China, province in Southwest China, the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is ...
, were described respectively by Franchet and
Delavay, on the same page of the same scientific article. In 1904
Finet and
Gagnepain thought these should both be regarded varieties of ''P. delavayi''. In 1953
F.C. Stern and
George Taylor described one more taxon, ''P. lutea'' var. ''ludlowii'', discovered in southeastern Tibet. In their description of ''Paeonia lutea'' var. ''ludlowii'', these authors indicate that it is distinctly different from variety ''lutea''. Recent analysis shows that these differences between ''ludlowii'' and the other described taxa in the ''P. delavayi''-group are consistent whilst the character states within the other taxa occur in any combination. Therefore Hong concludes that ''ludlowii'' should be acknowledged as a distinct species, while the other taxa cannot be upheld and should be synonymized with ''P. delavayi''.
Phylogeny
''Paeonia'' is the only genus recognized in the family Paeoniaceae. Three sections are distinguished: an early branching ''Onaepia'' that consists of both native North American species ''
P. brownii'' and ''
P. californica'', section ''Paeonia'', which comprises all Eurasian herbaceous species, and the section ''
Moutan'', which includes all woody species from China, including Tibet. These relations are represented by the following tree.
Etymology
The species was named in his honor
Frank Ludlow
Frank Ludlow OBE (10 August 1885 – 25 March 1972) was an English officer stationed in the British Mission at Lhasa and a naturalist.
Life
He was born in Chelsea, London and studied at West Somerset County School and Sidney Sussex College, Ca ...
who collected seed of ''Paeonia ludlowii'' in the Tsangpo Valley (upper
Brahmaputra river
The Brahmaputra is a trans-boundary river which flows through Tibet, northeast India, and Bangladesh. It is also known as the Yarlung Tsangpo in Tibetan, the Siang/Dihang River in Arunachali, Luit in Assamese, and Jamuna River in Bangla. It ...
) in 1936, after which it became for the first time known to western science, on his expedition with Major George Sherriff in South-East Tibet.
Distribution and ecology
''Paeonia ludlowii'' is an endemic that is restricted to the
Nyingchi
Nyingchi (), also known as Linzhi and as Nyingtri, is a prefecture-level city in the southeast of the Tibet Autonomous Region in China. The administrative seat of Nyingchi is Bayi District.
Nyingchi is the location of Buchu Monastery.
Economy ...
,
Mainling and
Lhünzê counties of South-East Tibet. It grows in open forests, and thickets on dry rocky slopes at elevations of 3000-3500m.
Individual populations are small in area but have a large number of individuals. Because the seeds are quite large, almost all seeds germinate close to the parent, and are often found in a large density. Perhaps rats are the most effective mains of seed dispersal to somewhat distanced new locations.
Cultivation
''Paeonia ludlowii'' is sometimes grown as an ornamental, mostly for its delicate foliage. In cultivation, it does best in fertile, neutral to slightly alkaline, well-drained soil. Specimens prefer to be planted deep and dislike too much water. In early spring and during summer
high-potash liquid feed stimulates richer flowering.
When growing the species from seed, these can best first be soaked, mixed with damp
vermiculite
Vermiculite is a hydrous phyllosilicate mineral which undergoes significant expansion when heated. Exfoliation occurs when the mineral is heated sufficiently, and commercial furnaces can routinely produce this effect. Vermiculite forms by the wea ...
, and kept at room temperature until root emerges after one to three months. If kept cool afterwards, the shoot appears after a further two to three months. When these are planted into separate pots immediately and grown in daylight results are generally good.
The shoot only appears at a root length of at least 6 cm has developed. The
epicotyl An epicotyl is important for the beginning stages of a plant's life. It is the region of a seedling stem above the stalks of the seed leaves of an embryo plant. It grows rapidly, showing hypogeal germination, and extends the stem above the soil surf ...
remains
dormant until the
GA3/
ABA ratio is sufficiently different.
Tree peonies in general can suffer from peony wilt (''
Botrytis paeoniae'', a grey mould blight) and
verticillium wilt
Verticillium wilt is a wilt disease affecting over 350 species of eudicot plants. It is caused by six species of ''Verticillium'' fungi: ''V. dahliae'', ''V. albo-atrum'', ''V. longisporum'', ''V. nubilum'', ''V. theobromae'' and ''V. tricorpu ...
, which may cause wilting and dieback of young shoots. In infected soils,
honey fungus
''Armillaria'' is a genus of fungi that includes the '' A. mellea'' species known as honey fungi that live on trees and woody shrubs. It includes about 10 species formerly categorized summarily as ''A. mellea''. ''Armillarias'' are long-l ...
can cause instant death.
Use
The species is used as a traditional medicine, and local people dig it up for its root bark. Exploitation by people from other parts of China is a serious threat to the survival of this species.
It is sometimes used as an ornamental for its ferny foliage in botanical gardens and by plant collectors.
References
{{Taxonbar, from=Q651777
Garden plants
Flora of China
Plants described in 1953
ludlowii