Clerodendrum

Clerodendrum is a genus of flowering plants formerly placed in the family Verbenaceae, but now considered to belong to the Lamiaceae (mint) family. Its common names include glorybower, bagflower and bleeding-heart. It is currently classified in the subfamily Ajugoideae, being one of several genera transferred from Verbenaceae to Lamiaceae in the 1990s, based on phylogenetic analysis of morphological and molecular data.
Estimates of the number of species in Clerodendrum vary widely, from about 150 to about 450. This is partly because about 30 species have been transferred to Rotheca, about 30 more to Volkameria, and 1 to Ovieda. The type species for the genus is Clerodendrum infortunatum. It is native to Sri Lanka and the Andaman Islands.
The genus is native to tropical and warm temperate regions of the world, with most of the species occurring in tropical Africa and southern Asia, but with a few in the tropical Americas and northern Australasia, and a few extending north into the temperate zone in eastern Asia.
They are shrubs, lianas, and small trees, usually growing to tall, with opposite or whorled leaves. C. floribundum can grow to tall. Clerodendrum fistulosum and Clerodendrum myrmecophila have hollow stems that are inhabited by ants. Clerodendrum trichotomum is a common ornamental in warmer parts of the world. Eight other species are also grown in the tropics for their abundant and attractive flowers. One of these, Clerodendrum macrostegium, suckers abundantly from the roots, often producing a thicket within a few years.
The following species are cultivated in the UK:
C. chinense
C. splendens
C. thomsoniae
C. trichotomum
Clerodendrum species are used as food plants by the larvae of some Lepidoptera species including Endoclita malabaricus and Endoclita sericeus. Both butterflies and hummingbirds are often attracted to blooming clerodendrum.
Description
The following description is based on the one by Yuan et alii (2010) and applies to only the monophyletic circumscription of Clerodendrum.
Clerodendrum is a genus of small trees, shrubs, lianas, and subherbaceous perennials. Leaves decussate or whorled, never spiny as in some close relatives.
Inflorescence usually terminal. Sepals usually connate, often colored, usually accrescent. Corolla red to yellow, pink, or white. Corolla tube 5-lobed, the lobes usually unequal.
Stamens 4 (rarely 5), usually in 2 pairs of unequal length and projecting well beyond the mouth of the corolla.
Ovary incompletely 4-locular. Ovules 4. Style terminal on the ovary, bifid.
Fruit a drupe, usually with 4 grooves or lobes, 4-seeded (rarely 2-seeded by abortion).
Pollination
Clerodendrum and its relatives have an unusual pollination syndrome which avoids self-pollination. This mating system combines dichogamy and herkogamy.
The flowers are protandrous. When the flower opens, the stamens stand erect, parallel to the central axis of the flower, while the style bends over, holding the stigma beyond the rim of the corolla. After the pollen is shed, the stamens curl up or bend over, and the style straightens out, bringing the stigma to the center of the flower. Except for Aegiphila, which is heterostylous, this breeding strategy is shared by all members of the clade consisting of Kalaharia, Clerodendrum, Volkameria, Aegiphila, Ovieda, Tetraclea, and Amasonia.
History
Clerodendrum was named by Linnaeus in Species Plantarum in 1753. The name is derived from two Greek words, kleros, meaning "chance or fate" or "clergy", and dendron, "a tree". It refers to the considerable variation in reports of the usefulness of Clerodendrum in medicine, and also to the fact the trees were used for religious purposes in Asia.
Regional revisions of Clerodendrum have been done for local floras, but the last monograph of the entire genus was by John Isaac Briquet in 1895. He recognized about 90 species, defining the genus broadly to include species that others had placed in Rotheca, Volkameria, and Ovieda. His circumscription was followed by most authors for the next 100 years, even though it was widely believed to be problematic.
In 1997, phylogenetic analysis of DNA data showed that Clerodendrum, as then understood, was polyphyletic. This situation was remedied in 1998 with the revival of Rotheca. This taxonomic change was based on previous work and on a molecular phylogenetic study that was not published until the following year.
In 2004, a study of DNA sequences showed that the monospecific Australian genus Huxleya was embedded in a clade of Clerodendrum species that had formerly been placed in Volkameria. Huxleya was then sunk into synonymy with Clerodendrum. The 2004 study sampled Aegiphila, Tetraclea, and Amasonia, three New World genera of Ajugoideae that had not previously been sampled for DNA. The results of this study cast doubt, once again, upon the monophyly of Clerodendrum.
In 2010, a study of four chloroplast DNA intergenic spacers showed that part of Clerodendrum was closer to the New world genera than to other Clerodendrum, and that one species of Clerodendrum was nested within the clade of New World genera. The authors of this study resurrected the genus Volkameria and assigned to it about 30 species that had been in Clerodendrum. They also resurrected Ovieda as a monotypic genus consisting of Ovieda spinosa. Volkameria and Ovieda had been erected by Linnaeus in 1753. Modern cladistic analysis has largely vindicated his concepts of Clerodendrum and its relatives.
Traditional medicinal use
Clerodendrum glandulosum. Coleb leaf aqueous extract is traditionally used by people of North-East India to alleviate symptoms of diabetes, obesity and hypertension.
Among the Hmar and Zomi tribes in the North East India Anphui(Clerodendrum) is also being used as a dish/curry.
Systematics
Clerodendrum is strongly supported as monophyletic in molecular phylogenetic analyses. It consists of two clades, each of which receives strong bootstrap support. One clade contains mostly African species. The other is mostly Asian. The African and Asian groups can not confidently be divided into sections without more extensive sampling of taxa in phylogenetic studies. The Madagascan species, in particular, are poorly studied.
It appears that the long, narrow corolla tube evolved only once in Clerodendrum, and appeared again, among its relatives, in Ovieda.
Species
Plants of the World Online recognises 258 species within this genus, as follows.
Clerodendrum abilioi
Clerodendrum adenocalyx
Clerodendrum adenophysum
Clerodendrum africanum
Clerodendrum albiflos
Clerodendrum alboviolaceum
Clerodendrum andamanense
Clerodendrum anomalum
Clerodendrum apayaoense
Clerodendrum arenarium
Clerodendrum atlanticum
Clerodendrum aucubifolium
Clerodendrum barba-felis
Clerodendrum baronianum
Clerodendrum baumii
Clerodendrum bellum
Clerodendrum bingaense
Clerodendrum bipindense
Clerodendrum boivinii
Clerodendrum bosseri
Clerodendrum brachyanthum
Clerodendrum brachystemon
Clerodendrum bracteatum
Clerodendrum brassii
Clerodendrum brunfelsiiflorum
Clerodendrum brunnescens
Clerodendrum brunsvigioides
Clerodendrum buchananii
Clerodendrum buchneri
Clerodendrum buettneri
Clerodendrum bungei
Clerodendrum calamitosum
Clerodendrum canescens
Clerodendrum capitatum
Clerodendrum carnosulum
Clerodendrum caryopteroides
Clerodendrum cauliflorum
Clerodendrum cecil-fischeri
Clerodendrum cephalanthum
Clerodendrum chamaeriphes
Clerodendrum chartaceum
Clerodendrum chinense
Clerodendrum chlorisepalum
Clerodendrum cochinchinense
Clerodendrum colebrookeanum
Clerodendrum comans
Clerodendrum confine
Clerodendrum corbisieri
Clerodendrum costatum
Clerodendrum cuspidatum
Clerodendrum cyrtophyllum
Clerodendrum dauphinense
Clerodendrum decaryi
Clerodendrum deflexum
Clerodendrum dembianense
Clerodendrum densiflorum
Clerodendrum denticulatum
Clerodendrum dependens
Clerodendrum dewittei
Clerodendrum dinklagei
Clerodendrum disparifolium
Clerodendrum dusenii
Clerodendrum ekmanii
Clerodendrum elbertii
Clerodendrum elliotii
Clerodendrum emirnense
Clerodendrum erectum
Clerodendrum ervatamioides
Clerodendrum eucalycinum
Clerodendrum eupatorioides
Clerodendrum excavatum
Clerodendrum farafanganense
Clerodendrum fasciculatum
Clerodendrum filipes
Clerodendrum finetii
Clerodendrum fistulosum
Clerodendrum floribundum
Clerodendrum formicarum
Clerodendrum fortunatum
Clerodendrum frutectorum
Clerodendrum fugitans
Clerodendrum fuscum
Clerodendrum galeatum
Clerodendrum garrettianum
Clerodendrum gaudichaudii
Clerodendrum geoffrayi
Clerodendrum gibbosum
Clerodendrum giganteum
Clerodendrum globosum
Clerodendrum globuliflorum
Clerodendrum godefroyi
Clerodendrum grayi
Clerodendrum grevei
Clerodendrum griffithianum
Clerodendrum haematolasium
Clerodendrum hahnianum
Clerodendrum hainanense
Clerodendrum harmandianum
Clerodendrum hastatum
Clerodendrum hendersonii
Clerodendrum hettae
Clerodendrum hexangulatum
Clerodendrum hildebrandtii
Clerodendrum hircinum
Clerodendrum hiulcum
Clerodendrum humbertii
Clerodendrum inaequipetiolatum
Clerodendrum indicum
Clerodendrum infortunatum
Clerodendrum insolitum
Clerodendrum intermedium
Clerodendrum involucratum
Clerodendrum izuinsulare
Clerodendrum japonicum
Clerodendrum johnstonii
Clerodendrum johorense
Clerodendrum kaichianum
Clerodendrum kamhyoae
Clerodendrum kampotense
Clerodendrum kanichi
Clerodendrum katangensis
Clerodendrum kauderni
Clerodendrum kiangsiense
Clerodendrum kinabaluense
Clerodendrum klemmei
Clerodendrum kwangtungense
Clerodendrum laciniatum
Clerodendrum laevifolium
Clerodendrum lanceoliferum
Clerodendrum lanessanii
Clerodendrum lankawiense
Clerodendrum lanuginosum
Clerodendrum lastellei
Clerodendrum laxiflorum
Clerodendrum lecomtei
Clerodendrum leucobotrys
Clerodendrum leucophloeum
Clerodendrum lindenianum
Clerodendrum lindleyi
Clerodendrum lloydianum
Clerodendrum longiflorum
Clerodendrum longisepalum
Clerodendrum lutambense
Clerodendrum luteopunctatum
Clerodendrum macrocalycinum
Clerodendrum macrostegium
Clerodendrum madagascariense
Clerodendrum magnificum
Clerodendrum magnoliifolium
Clerodendrum mananjariense
Clerodendrum mandarinorum
Clerodendrum mandrarense
Clerodendrum mannii
Clerodendrum manombense
Clerodendrum margaritense
Clerodendrum melanocrater
Clerodendrum micans
Clerodendrum mildbraedii
Clerodendrum minahassae
Clerodendrum mindorense
Clerodendrum moramangense
Clerodendrum morigono
Clerodendrum multibracteatum
Clerodendrum myrianthum
Clerodendrum myrmecophilum
Clerodendrum myrtifolium
Clerodendrum nhatrangense
Clerodendrum nicolsonii
Clerodendrum nipense
Clerodendrum nutans
Clerodendrum ohwii
Clerodendrum palmatolobatum
Clerodendrum paniculatum
Clerodendrum parvitubulatum
Clerodendrum parvulum
Clerodendrum paucidentatum
Clerodendrum pauciflorum
Clerodendrum peii
Clerodendrum peregrinum
Clerodendrum perrieri
Clerodendrum petasites
Clerodendrum petunioides
Clerodendrum phlomidis
Clerodendrum phyllomega
Clerodendrum pierreanum
Clerodendrum pleiosciadium
Clerodendrum poggei
Clerodendrum polyanthum
Clerodendrum polycephalum
Clerodendrum porphyrocalyx
Clerodendrum praetervisa
Clerodendrum premnoides
Clerodendrum preslii
Clerodendrum pubiflorum
Clerodendrum pusillum
Clerodendrum putre
Clerodendrum pygmaeum
Clerodendrum pynaertii
Clerodendrum pyrifolium
Clerodendrum quadriloculare
Clerodendrum ramosissimum
Clerodendrum revolutum
Clerodendrum ridleyi
Clerodendrum ringoetii
Clerodendrum robecchii
Clerodendrum robustum
Clerodendrum roseiflorum
Clerodendrum rotundifolium
Clerodendrum rubellum
Clerodendrum rumphianum
Clerodendrum rusbyi
Clerodendrum sakaleonense
Clerodendrum sarawakanum
Clerodendrum sassandrense
Clerodendrum sayapense
Clerodendrum schmidtii
Clerodendrum schweinfurthii
Clerodendrum sessilifolium
Clerodendrum silvanum
Clerodendrum silvestre
Clerodendrum singwanum
Clerodendrum sinuatum
Clerodendrum smitinandii
Clerodendrum speciosissimum
Clerodendrum splendens
Clerodendrum subpeltatum
Clerodendrum subreniforme
Clerodendrum subtruncatum
Clerodendrum sylvae
Clerodendrum sylvestre
Clerodendrum tanganyikense
Clerodendrum tatei
Clerodendrum ternatum
Clerodendrum thomsoniae
Clerodendrum thouarsii
Clerodendrum thyrsoideum
Clerodendrum tibetanum
Clerodendrum tomentellum
Clerodendrum tomentosum
Clerodendrum tonkinense
Clerodendrum toxicarium
Clerodendrum tracyanum
Clerodendrum trichanthum
Clerodendrum tricholobum
Clerodendrum trichotomum
Clerodendrum triflorum
Clerodendrum tubulosum
Clerodendrum umbellatum
Clerodendrum umbratile
Clerodendrum urticifolium
Clerodendrum villosicalyx
Clerodendrum villosum
Clerodendrum vinosum
Clerodendrum volubile
Clerodendrum wallii
Clerodendrum welwitschii
Clerodendrum williamsii
Clerodendrum yunnanense
Formerly placed here
Pseudocaryopteris foetida (D.Don) P.D.Cantino (as C. foetidum D.Don)
Rotheca incisa (Klotzsch) Steane & Mabb. (as C. incisum Klotzsch or C. macrosiphon Hook.f.)
Rotheca myricoides (Hochst.) Steane & Mabb. (as C. myricoides (Hochst.) Vatke or C. ugandense Prain)
Rotheca serrata (L.) Steane & Mabb. (as C. serratum (L.) Moon)
Volkameria aculeata L. (as C. aculeatum (L.) Schltdl.)
Volkameria glabra (E.Mey.) Mabb. & Y.W.Yuan (as C. glabrum E.Mey.)
Volkameria inermis L. (as C. inerme (L.) Gaertn.)
Volkameria ligustrina Jacq. (as C. ligustrinum (Jacq.) R.Br.)
Gallery
References
External links
Clerodendrum At:Index Nominum Genericorum At: References At: NMNH Department of Botany
Clerodendrum In: volume 2 Of: Species Plantarum At: Biodiversity Heritage Library
Flora of China: Clerodendrum
Taxa named by Carl Linnaeus
Lamiaceae genera