Hemigraphis

Abstract: Fourteen species originally described in the genus Hemigraphis are formally transferred to the genus Strobilanthes, following currently accepted generic delimitation in the family. Thirteen new combinations and one new name are proposed.

Abstract: Seventeen species are reported as new weeds for Peninsular Malaysia, namely Ageratum houstonianum Mill., Crassocephalum crepidioides (Benth.) S.Moore and Tithonia diversifolia (Hemsl.) A. Gray (Compositae), Brugmansia x candida Pers. (Solanaceae), Coccinia grandis (L.) J.Voigt and Melothria pendula L. (Cucurbitaceae), Crocosmia x crocosmiiflora (Burb. & Dean) N.E.Br. (Iridaceae), Cuphea ignea A.DC. (Lythraceae), Epilobium billarderianum Ser. subsp. cinereum (A.Rich.) Raven & Engelhorn (Onagraceae), Hemigraphis primulifolia (Nees) Fern.-Vill. (Acanthaceae), Pennisetum polystachion (L.) Schult. (Gramineae), Polygala paniculata L. (Polygalaceae), Polygonum perfoliatum L. (Polygonaceae), Potentilla indica (Andr.) Wolf. (Rosaceae), Ranunculus cantoniensis DC. (Ranunculaceae), Richardia brasiliensis Gomez (Rubiaceae) and Sagina japonica (Sw. ex Steud.) Ohwi (Caryophyllaceae). Several others, Asystasia gangetica (L.) T.Anderson subsp. micrantha (Nees) Ensermu (Acanthaceae), Cleome rutidosperma DC. (Cleomaceae), Clinopodium gracile (Benth.) Kuntze (Labiatae), Cuphea carthagenensis (Jacq.) J.F.Macbr. (Lythraceae), Justicia procumbens L. (Acanthaceae), Oxalis corniculata L. and O. barrelieri L. (Oxalidaceae), Persicaria capitata (Buch.-Ham. ex D.Don) H.Gross (Polygonaceae), and Youngia japonica (L.) DC. (Compositae), have become widespread. Two are of particular conservation concern because they threaten native habitats: Acacia mangium Willd. (Leguminosae) is invading Trengganu heath forest and increasing fire risk to this vulnerable vegetation type, while Pennisetum polystachion, an aggressive grass, is becoming dominant on Klang Gates Ridge and endangering rare and endangered species.

Abstract: Summary Ruellia is a large, pantropical group of herbs and shrubs that has undergone a long series of changes in classification. Soon after Linnaeus's original description the genus was divided into numerous segregate genera by Nees von Esenbeck and by others. Later Bentham sunk i8 Neesian genera in his expanded concept of Ruellia, and this circumscription has come to be the accepted definition for the plants. Recently Bremekamp revived a number of old segregate groups and described several new ones. He believes Ruellia sensu lato is an unwieldy and unnatural assemblage of taxa. Experimental hybridizations have established the existence of species-complexes (ecospecies) and species-groups (comparia) in Ruellia. The latter are genetically isolated from other species-groups, and taxonomically they correspond to certain segregate genera. There is evidence that North American taxa are closely related to tropical species. Since numerous species can be artificially hybridized, application of the ecotype concept may provide a practical means of identifying natural species-groups. Present evidence suggests that Ruellia, as generally understood, is not a natural, phyletic, unit. The genus Ruellia was established by Linnaeus (I735: 41) for a small group of mostly erect, tropical herbs or shrubs with opposite, entire leaves and violet or lilac flowers. Linnaeus's original concept was based on Plumier (I703: p. I2), and Plumier's plant is clearly Ru'ellia tuberosa, a wide-spread tropical American species. It has been chosen as the lectotype for Ruellia (Britton & Brown, I913: 241). Only eight species were included by Linnaeus in his "Species Plantarum" (I753: 634), and four of these were transferred later to other genera. The remaining four species were placed in a new genus by Nees (1812: 75, 8i), Dipteracanthus. Ruellia, as accepted by Nees (in, de Candolle, 1847: 143) was in reality Hemigraphis, a very different genus from that originally described by Linnaeus. Both Nees and Oersted (I854: I22, I23) divided Ruellia into a number of small and moderate-sized genera, and the original generic concept was not used. Following this period of "fracture taxonomy" during the first half of the i9th century, Anderson (I864: 24; I867: 460) revived the Linnaean genus, and Bentham (in, Bentham and Hooker, 1876: I077) laid the foundation for the generally accepted interpretation of these plants. Eighteen genera, chiefly Neesian in origin, were sunk under Ruellia. Bentham maintained that the characters of these genera were congruent, and they were connected by intermediate forms. This broadened concept was ac