Re-shaping Mallotus [paRt 1]: expanded ciRcuMscRiption and Revision of the genus coRdeMoya (euphoRbiaceae)

A recent phylogenetic study based on DNA sequence data detected a well-supported clade of a number of Mallotus species together with the genus Cordemoya . This clade is distinct from the large Mallotus s.s. clade. In this paper, Cordemoya (formerly monotypic with C. integrifolia from the Mascarene Islands) is expanded with sixteen additional species previously assigned to Mallotus . Taxa transferred to Cordemoya are: Mallotus sections Hancea and Oliganthae from Asia and M. baillonianus , M. capuronii , and M. spinulosus from Madagascar. The genus Cordemoya can be distinguished from Mallotus s.s. by the presence of pollen with areolate ornamentation with scabrae (perforate/micro-reticulate ornamentation with scabrae in the sample of Mallotus s.s. studied up to now) and of capitate glandular hairs with multicellular stalks and sessile peltate-stellate hairs with a central cell (spherical to disc-shaped multicellular glandular hairs in Mallotus ). In the new circumscription of Cordemoy a two subgenera are recognized: Cordemoya from Madagascar and Mascarenes and Diplochlamys from Asia. The latter is divided into two sections: Diplochlamys (former sect. Hancea ), and Oliganthae . A taxonomic revision of part of these taxa is provided (excl. section Diplochlamys ); descriptions, distribution maps, habit drawings and a key are included.


INTRODUCTION
In the last classification of Mallotus Lour. by Airy Shaw (1968), the genus was subdivided into eight sections based on few morphological characters. However, two phylogenetic studies have recently contributed to the knowledge of the boundaries of the genus Mallotus and its relationships with related genera, namely with the members of subtribe Rottlerinae Meisn. (Webster, 1994c) and the genus Macaranga Thouars. An analysis of morphological data (Slik & Van Welzen, 2001b) indicated that the Asian sections Hancea (Seem.) Pax & K. Hoffm. (12 spp.) and Oliganthae Airy Shaw (monotypic) might not belong to the same clade as the other Mallotus sections and the genus Macaranga. A study of DNA sequence data with a more extensive taxon sampling (Kulju et al., in press-b) confirmed this result, grouping these two sections together with three Mallotus species (= Deuteromallotus) endemic to Madagascar (M. baillonianus Müll.Arg., M. capuronii (Léandri) McPherson, and M. spinulosus

INFRAGENERIC CLASSIFICATION
The rank of subgenus was assigned to the two strongly supported and geographically distinct Cordemoya clades present in the phylogeny of Fig. 5 Morphologically, these three taxa can be distinguished by leaf arrangement. In subg. Cordemoya the leaves are predominantly opposite and similar in shape, but one only slightly smaller than the other (sometimes the leaves are alternate). Additionally, it is the only subgenus which has sessile peltate-stellate hairs with a central cell. The members of section Diplochlamys also have opposite leaves, but the smaller leaf of each pair is reduced and dissimilar, resembling a stipule. Section Oliganthae always has alternate leaves. Sections Diplochlamys and Oliganthae have capitate glandular hairs with multicellular stalks, which are also present in C. capuronii of subgenus Cordemoya. Further characters separating section Diplochlamys from section Oliganthae are branches with conspicuously swollen nodes (slender in Oliganthae), interpetiolar stipules (axillary in Oliganthae), leaf blade not peltate (subpeltate in Oliganthae), axillary inflorescences (ramiflorous and axillary in Oliganthae), and fruits opening septicidally-loculicidally (loculicidally-septicidally in Oliganthae).

TAXONOMIC HISTORY
The first generic name for the basal (Cordemoya) clade is Boutonia Bojer (1837), but this name was invalidly described, the only descriptive 'character' casually mentioned is 'shrub'. The validation in 1846 by Bojer created a later homonym, because De Candolle (1838) had used Boutonia for an Acanthaceae.
The earliest legitimate generic name is Cordemoya Baill. (1861), which therefore is adopted here. It was proposed for Ricinus integrifolius Willd. from Mauritius. Baillon (1861) transferred the latter species to his new genus Cordemoya and added C. acuminata Baill. from Madagascar. Several years later Baillon (1891a) moved these two species to Echinus Lour. as sect. Cordemoya.
Habitat & Ecology -Locally in understory of evergreen forest. Altitude: sea level up to 1400 m. Flowering: February to May; fruiting: June to January.
Note -Miquel in 1861 mentions that the Zollinger collection cited in 1859 comes from Sumatra and not from Java. Additionally he mentions two collections by Teijsmann in Sumatra. We did not find any collections with the name Mappa rhyncophylla Miq. from Zollinger in Sumatra, therefore, we have appointed as lectotype one of the collections from Teijsmann in Sumatra.