Piero G. Delprete

A trnL-F cpDNA sequence study of the Condamineeae-Rondeletieae-Sipaneeae complex with implications on the phylogeny of the Rubiaceae.

DNA sequences from the chloroplast trnL-F region of 154 Rubiaceae and 11 outgroup taxa were analyzed cladistically. An emphasis was placed on the tribes Rondeletieae, Sipaneeae, and Condamineeae. Sipaneeae are not close to Rondeletieae and belong in the Ixoroideae. There is no support for a widely distributed Rondeletieae in a broad sense. Instead, Rondeletieae sensu stricto form an almost entirely Antillean clade. Support was found for the separation of Arachnothryx, Rogiera, Roigella, and Suberanthus from Rondeletia. The Guettardeae as well as Gonzalagunia are found close to a complex formed by Arachnothryx, Javorkaea, and Rogiera. Condamineeae, in a strict sense, belongs in the Ixoroideae. A number of Rondeletieae genera should be transferred to Condamineeae or other parts of Ixoroideae. Support is found for an emended tribe Naucleeae, comprising several genera with spherical pseudanthia. For the first time, tribal or subfamilial affiliation based on molecular sequence data is suggested for Allenanthus, Blepharidium, Chione, Coutaportla, Dolichodelphys, Mazaea, Neobertiera, Neoblakea, Phialanthus, Phyllacanthus, Phyllomelia, Schmidtottia, and Suberanthus.

Molecular systematics of the Catesbaeeae-Chiococceae complex (Rubiaceae): Flower and fruit evolution and biogeographic implications

The classification of the Catesbaeeae and Chiococceae tribes, along with that of the entire Rubiaceae, has long been debated. The Catesbaeeae-Chiococceae complex (CCC) includes approximately 28 genera and 190 species primarily concentrated in the Greater Antilles (nearly 70% of the species), Central and South America, and in the western Pacific (three genera). Previous molecular studies, with broad sampling of the Rubiaceae, have shown the CCC to be a monophyletic group. The present study is a more detailed examination of the generic relationships within the CCC using two data sets, the nuclear ribosomal ITS regions and the trnL-F chloroplast intron and spacer. Maximum parsimony analyses lend further support to the previous hypotheses that the CCC is monophyletic and sister to Strumpfia maritima. However, within the complex several genera do not form monophyletic groups. Previous studies of the Rubiaceae suggest that the ancestral fruit type in the CCC is a multiseeded capsule. Indehiscent, fleshy fruits appear to have evolved three to four times within this lineage. Changes in floral morphologies within the complex tend to correspond to cladogenesis among and within genera. Finally, molecular analyses suggest one or possibly two long-distance dispersals from the Americas to the western Pacific.

THE RONDELETIA COMPLEX (RUBIACEAE): AN ATTEMPT TO USE ITS, RPS16, AND TRNL-F SEQUENCE DATA TO DELIMIT GUETTARDEAE, RONDELETIEAE, AND SECTIONS WITHIN RONDELETIA

Abstract In the present study, a molecular phylogeny of the Rondeletia L. complex (Rubiaceae, Rondeletieae) was constructed with the following main objectives: (1) to evaluate the sections of Rondeletia proposed by Fernández Zequeira; (2) to test if Stevensia Poit. belongs to the Rondeletieae s. str.; (3) to check if ITS data from Rondeletieae support previous phylogenetic results from trnL-F data regarding circumscription of Rondeletieae; and (4) to verify if Hodgkinsonia F. Muell. belongs to Guettardeae or elsewhere. Two analyses were performed, one with ITS sequences from 46 taxa in the Rondeletieae–Guettardeae complex, and the other with combined ITS, rps16, and trnL-F sequences of 21 taxa. Representatives of nine of the 10 sections of Rondeletia recognized by Fernández Zequeira were included in the ITS analysis. Five of her sections could be tested for monophyly. Support was only found for Rondeletia sect. Leoninae M. Fernández Zeq., while representatives from section Chamaebuxifoliae M. Fernández Zeq., section Hypoleucae Standl., and section Nipenses M. Fernández Zeq. together form a well-supported clade that could be distinguished also based on morphology. The latter clade is sister to Stevensia, which is thus placed within Rondeletia s. str. In addition, ITS sequence data confirm the separation of Rovaeanthus Borhidi from Rogiera Planch. Support is low for inclusion of Blepharidium Standl., Mazaea Krug & Urb., Phyllomelia Griseb., Rachicallis DC., part of Rogiera, and Suberanthus Borhidi & M. Fernández Zeq. in Rondeletieae. Rachicallis, Mazaea, and Phyllomelia form a clade with strong support. The tribe Rondeletieae s. str. was found to be monophyletic in all trees, although with low support; however, a re-delimitation of the tribe is proposed here based on this study and previous phylogenetic analyses. The monophyly for the tribe Guettardeae is weakly supported, with the inclusion of Arachnothryx Planch. (including Cuatrecasasiodendron Steyerm.), Gonzalagunia Ruiz & Pav., Hodgkinsonia, and Timonius DC. Although it was recently the subject of a molecular phylogenetic study, the tribe Guettardeae is still in need of a wide-ranging survey in order to confirm its monophyly and delimit its taxonomic boundaries. Because Cuatrecasasiodendron was found within the Arachnothryx clade, the two genera are here synonymized as Arachnothryx, and in turn positioned within the tribe Guettardeae. In addition, based on herbarium and field studies, the two species described under Cuatrecasasiodendron (C. spectabile Steyerm. and C. colombianum Standl. & Steyerm.) are treated as synonyms to the new combination Arachnothryx spectabilis (Steyerm.) Rova, Delprete & B. Bremer, which is proposed here.

Anatomical and chemical analyses of leaf secretory cavities of Rustia formosa (Rubiaceae).

Foliar secretory cavities, commonly called leaf pellucid glands, have been reported in many families of vascular plants. In the Rubiaceae, these structures have only been found in the sister genera Rustia and Tresanthera, which are also anomalous within the family because they have poricidal anthers, and in the distantly related Heterophyllaea. General leaf anatomy, with particular attention to secretory cavities, as well as the chemical analysis of the secreted substances of Rustia formosa, is presented here for the first time. The secretory structures have been found in the lamina between the palisade and spongy parenchymas and in the cortical region of the petiole. The chemical analysis showed that the essential oil secreted is a complex mixture of at least 75 components, mostly of sesquiterpenoid composition. Illustrations of the leaf anatomy, details of the secretory structures of Rustia formosa, a gas chromatogram, and a table of the principal components of the leaf essential oil are included.

NOTES ON CALYCOPHYLLOUS RUBIACEAE. PART III. SYSTEMATIC POSITION OF THE MONOTYPIC MEXICAN GENUS COSMOCALYX AND NOTES ON THE CALYCOPHYLL DEVELOPMENT

The systematic position ofCosmocalyx, heretofore treated as agenus incertae sedis, is discussed. The morphological features ofCosmocalyx suggest strong similarities to various genera of the Hamelieae, to which it is compared and where it is placed. A complete description ofCosmocalyx, observations on its phenology, and comments on calyx and fruit development are presented and illustrated.

Revision and typification of Brazilian Augusta (Rubiaceae, Rondeletieae), with ecological observations on the riverine vegetation of the cerrado and Atlantic forests

A revision of Brazilian Augusta and general comments on the systematics of this genus are presented. The complex taxonomic history of this taxon has caused confusion over its correct nomenclature. The peculiar geographic distribution of Augusta has stimulated field observations and analysis of the ecology of the Brazilian ecosystems where this taxon occurs, which are here presented. The five Brazilian species of Augusta described by Pohl are here treated as ecotypes of A. longifolia. This species has two distinct varieties: var. Longifolia, widespread throughout the Brazilian cerrado, and var. parvifolia, endemic to the Atlantic forest near Rio de Janeiro. Typification, list of representative specimens, and distribution map of A. longifolia are also included.

RIODOCEA (RUBIACEAE, GARDENIEAE), A NEW GENUS FROM THE BRAZILIAN ATLANTIC FOREST

The genusRiodocea is here described from material collected in the várzea forest of the Rio Doce Valley, northern Espírito Santo.Riodocea is a monotypic genus probably related to the Amazonian endemicKutchubaea. A line drawing shows general morphology and photomicrographs show pollen morphology ofRiodocea pulcherrima. Distribution maps ofRiodocea andKutchubaea are included.The valley of the Rio Doce is here included in the Bahian Hylaea, defined as a subregion of the Brazilian Atlantic forest. The connections between the Amazonian Hylaea and the Bahian Hylaea are discussed.

Taxonomic History, Morphology, and Reproductive Biology of the Tribe Posoquerieae (Rubiaceae, Ixoroideae)1

Abstract The tribe Posoquerieae was recently described to include the genera Posoqueria Aubl. and Molopanthera Turcz. based on floral morphology, palynology, the presence of the pollen catapult mechanism, and molecular phylogenetic evidence. The floral morphology of these two genera was first recognized as unique in the Rubiaceae by Schumann. Both genera have stamens initially united into an ellipsoidal structure held at an oblique position, with the ventral stamen that springs forward when touched, while the two lateral stamens fold outward. Since their descriptions were published, Posoqueria and Molopanthera have been positioned in several distantly related tribes within the Rubiaceae. The close relationship between the two genera was only recently revealed by molecular phylogenetic studies. The taxonomic history of Posoqueria and Molopanthera is reviewed, and a general morphological comparison (particularly of stamen morphology and pollen catapult mechanism, and observations about pollination biology) of both genera is presented here. The pollen catapult mechanism of Molopanthera is described here in detail for the first time and concluded to be practically identical to that of Posoqueria.

Phylogenetic Placement of the Tribe Retiniphylleae Among the Subfamily Ixoroideae (Rubiaceae)1

Abstract The tribe Retiniphylleae and its single genus Retiniphyllum Bonpl. contains 22 species of shrubs and small trees that grow in white sand soils mostly in the Guayana Region of South America. The circumscription of the tribe is based on the diagnostic characteristic of two collateral and pendulous ovules per locule, a rare condition in the Rubiaceae. However, for the same reason, its placement within the family has been controversial. The monophyly and systematic position of the tribe Retiniphylleae and Retiniphyllum were tested based on a phylogenetic analysis of trnL-F and rps16 sequence data. The results confirm the monophyly of the tribe and genus Retiniphyllum. The tribe is placed sister to the core members of the subfamily Ixoroideae s. str. The genera Botryarrhena Ducke and Scyphiphora C. F. Gaertn. are not related to the tribe Retiniphylleae, as formerly hypothesized.

The Cuban endemic genera Ariadne, Mazaea, Acunaeanthus, Phyllomelia (Rondeletieae), and Eosanthe (Rubiaceae)

After detailed morphological comparison, the generaMazaea (incl.Neomazaea) andAriadne are considered to be synonymous, for which a new combination,M. shaferi, is provided.Acunaeanthus is maintained as a separate monotypic genus.Phyllomelia, previously treated asgenus incertae sedis, is here transferred to the Rondeletieae, and believed to be closely related toMazaea. The systematic position ofEosanthe remains dubious until fertile collections become available. Complete descriptions, synonymies, typifications, and distributions ofMazaea, Acunaeanthus, Phyllomelia, andEosanthe are presented, andMazaea andPhyllomelia are illustrated.