Rotheca

Rotheca is a genus of flowering plants in the family Lamiaceae.^[1] Estimates of the number of species in the genus vary from about 35 ^[2] to as many as 60.^[1] Three of the species are native to tropical Asia, with the rest occurring in Sub-Saharan Africa.^[2] The type species for the genus is Rotheca serrata. It had originally been named Rotheca ternifolia, but this name is now considered illegitimate.^[3]

Rotheca
Rotheca myricoides
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Lamiales
Family:	Lamiaceae
Subfamily:	Ajugoideae
Genus:	Rotheca Rafinesque
Type species
Rotheca serrata Rafinesque
Species
See text
Synonyms
Cyclonema Hochst.

Rotheca myricoides is native to tropical East Africa and is cultivated as an ornamental throughout the tropics.^[4] Rotheca serrata is from tropical Asia and has some medicinal use there.^[2]

In the 20th century, Rotheca was rarely recognized as separate from Clerodendrum. Rotheca was revived in 1998 as a result of phylogenetic analysis of DNA sequences. It can easily be distinguished from Clerodendrum by a combination of morphological characters.^[3]

Description

The following description is adapted from the most recent monograph on Lamiaceae.^[1]

Rotheca is a genus of shrubs, subshrubs, and herbaceous perennial plants, with a few becoming lianas or small trees. They emit an unpleasant odor when damaged. The leaves are opposite or whorled, and sessile or with a short petiole. The calyx is actinomorphic or nearly so, and not accrescent as in some related genera. The corolla is blue, purple, or white, (rarely yellow), and 5-lobed. The abaxial lobe is often larger and different in color. The four stamens are long-exserted. The ovary is unlobed at anthesis, becoming lobed during maturity. The fruit is 4-lobed and resembles a drupe, but eventually separates into four 1-seeded mericarps.

Taxonomy

Rotheca was named by Rafinesque in 1838.^[5] The name is a Latinization of a Malayalam name meaning "small teak".^[3] The Indian (Malayalam) name has had widely variant spellings.

In 1895, John Isaac Briquet included Rotheca in his rather broad circumscription of Clerodendrum.^[6] Briquet's treatment was generally followed for the next 100 years, but doubts about it were often expressed.^[7] The genus Rotheca was revived in 1998, based on molecular phylogenetic work, some of which was not published until 1999.^[8] In this work, it was shown that inclusion of Rotheca in Clerodendrum renders the latter polyphyletic.

Species

One commonly consulted species list provides only a few examples.^[9] The transfer of species from Clerodendrum to Rotheca continues in a piecemeal fashion, and is mostly for the compilation of local floras.^[10] As of July 2015^[update], The Plant List accepts the following species:^[11]

• Rotheca alata (Gürke) Verdc.
• Rotheca amplifolia (S.Moore) R.Fern.
• Rotheca aurantiaca (Baker) R.Fern.
• Rotheca bukobensis (Gürke) Verdc.
• Rotheca caerulea (N.E.Br.) P.P.J.Herman & Retief
• Rotheca calundensis (R.Fern.) R.Fern.
• Rotheca commiphoroides (Verdc.) Steane & Mabb.
• Rotheca cuneiformis (Moldenke) P.P.J.Herman & Retief
• Rotheca cyanea (R.Fern.) R.Fern.
• Rotheca farinosa (Roxb.) Govaerts
• Rotheca hirsuta (Hochst.) R.Fern.
• Rotheca incisa (Klotzsch) Steane & Mabb.
• Rotheca kissakensis (Gürke) Verdc.
• Rotheca louwalbertsii (P.P.J.Herman) P.P.J.Herman & Retief
• Rotheca luembensis (De Wild.) R.Fern.
• Rotheca makanjana (H.J.P.Winkl.) Steane & Mabb.
• Rotheca mendesii (R.Fern.) R.Fern.
• Rotheca myricoides (Hochst.) Steane & Mabb. (syn. Clerodendrum ugandense Prain) – Butterfly Bush
• Rotheca pilosa (H.Pearson) P.P.J.Herman & Retief
• Rotheca prittwitzii (B.Thomas) Verdc.
• Rotheca quadrangulata (B.Thomas) R.Fern.
• Rotheca reflexa (H.Pearson) R.Fern.
• Rotheca rupicola (Verdc.) Verdc.
• Rotheca sansibarensis (Gürke) Steane & Mabb.
• Rotheca serrata (L.) Steane & Mabb.
• Rotheca suffruticosa (Gürke) Verdc.
• Rotheca taborensis (Verdc.) Verdc.
• Rotheca tanneri (Verdc.) Verdc.
• Rotheca teaguei (Hutch.) R.Fern.
• Rotheca vanprukii (Craib) Leerat. & Chantar.
• Rotheca verdcourtii (R.Fern.) R.Fern.
• Rotheca violacea (Gürke) Verdc.
• Rotheca wildii (Moldenke) R.Fern.