Phialiphora Groeninckx is described as a new herbaceous genus of Rubiaceae, endemic to NW Madagascar. The genus belongs to the predominantly herbaceous tribe Spermacoceae, and comprises two species: P. bevazahensis Groeninckx and P....
morePhialiphora Groeninckx is described as a new herbaceous genus of Rubiaceae, endemic to NW Madagascar. The genus belongs to the predominantly herbaceous tribe Spermacoceae, and comprises two species: P. bevazahensis Groeninckx and P. capitulata Groeninckx. Phialiphora is unique within Spermacoceae in having heart-shaped placentas distally attached to the septum with a stalk. The generic name refers to the involucrate head-like inflorescences. Molecular data, based on atpB-rbcL, petD, rps16, and trnL-trnF sequences, demonstrate that Phialiphora belongs to the Hedyotis-Oldenlandia complex of the tribe Spermacoceae. The genus shares a common ancestor with the Madagascan endemics Astiella Jovet, Thamnoldenlandia Groeninckx and Amphistemon Groeninckx. Our study supports the hypothesis that the current diversity of Spermacoceae on Madagascar is the result of several independent colonisation events since the Eocene, most likely by long-distance dispersal from the African continent. A key to the genera of Spermacoceae on Madagascar is provided.
Page 1. Svst. Geogr. PI. 71: 455-492 (2001) Reinstatement of the Afro-Malagasy genus Coptosperma (Rubiaceae, Ixoroideae, Pavetteae) P. De Block*, J. Degreef & E. Robbrecht National Botanic Garden, Domein van Bouchout ...
Puff C, Robbrecht E, Buchner R, De Block P. 1996 A survey of secondary pollen presentation in the Rubiaceae. In: Robbrecht, E,, Puff, C,, Smets, E ed (s). Proc. 2nd Intn. Rubiaceae Conf. Meise. Opera Bot. Belg. 7. National Botanic Garden...
morePuff C, Robbrecht E, Buchner R, De Block P. 1996 A survey of secondary pollen presentation in the Rubiaceae. In: Robbrecht, E,, Puff, C,, Smets, E ed (s). Proc. 2nd Intn. Rubiaceae Conf. Meise. Opera Bot. Belg. 7. National Botanic Garden of Belgium: Meise. ...
Illumina assemblies of 4 endosymbionts identified from whole genome sequencing of leaves of the following Rubiaceae species: <em>Empogona congesta, Tricalysia hensii, Tricalysia lasiodelphys</em> and <em>Tricalysia...
moreIllumina assemblies of 4 endosymbionts identified from whole genome sequencing of leaves of the following Rubiaceae species: <em>Empogona congesta, Tricalysia hensii, Tricalysia lasiodelphys</em> and <em>Tricalysia semidecidua</em>. The phylogenetic relationships of these species were studied in Ly et al., 2020 (
https://doi.org/10.1371/journal.pone.0232295). Endosymbiots correspond to new Burkholderia species.
Background Leaf symbiosis is a phenomenon in which host plants of Rubiaceae interact with bacterial endophytes within their leaves. To date, it has been found in around 650 species belonging to eight genera in four tribes; however, the...
moreBackground Leaf symbiosis is a phenomenon in which host plants of Rubiaceae interact with bacterial endophytes within their leaves. To date, it has been found in around 650 species belonging to eight genera in four tribes; however, the true extent in Rubiaceae remains unknown. Our aim is to investigate the possible occurrence of leaf endophytes in the African plant genera Empogona and Tricalysia and, if present, to establish their identity. Methods Total DNA was extracted from the leaves of four species of the Coffeeae tribe (Empogona congesta, Tricalysia hensii, T. lasiodelphys, and T. semidecidua) and sequenced. Bacterial reads were filtered out and assembled. Phylogenetic analysis of the endophytes was used to reveal their identity and their relationship with known symbionts. Results All four species have non-nodulated leaf endophytes, which are identified as Caballeronia. The endophytes are distinct from each other but related to other nodulated and non-nodulated endophytes. An ...
In this data paper, we present a specimen-based occurrence dataset compiled in the framework of the Conservation of Endemic Central African Trees (ECAT) project with the aim of producing global conservation assessments for the IUCN Red...
moreIn this data paper, we present a specimen-based occurrence dataset compiled in the framework of the Conservation of Endemic Central African Trees (ECAT) project with the aim of producing global conservation assessments for the IUCN Red List. The project targets all tree species endemic or sub-endemic to the Central African region comprising the Democratic Republic of the Congo (DR Congo), Rwanda, and Burundi. The dataset contains 6361 plant collection records with occurrences of 8910 specimens from 337 taxa belonging to 153 genera in 52 families. Many of these tree taxa have restricted geographic ranges and are only known from a small number of herbarium specimens. As assessments for such taxa can be compromised by inadequate data, we transcribed and geo-referenced specimen label information to obtain a more accurate and complete locality dataset. All specimen data were manually cleaned and verified by botanical experts, resulting in improved data quality and consistency.
Background and aims – Rubieae is a tribe in the subfamily Rubioideae characterised by herbaceous plants with verticillate leaves and flowers with a rudimentary or absent calyx and a short, cup-shaped corolla. This is in contrast to the...
moreBackground and aims – Rubieae is a tribe in the subfamily Rubioideae characterised by herbaceous plants with verticillate leaves and flowers with a rudimentary or absent calyx and a short, cup-shaped corolla. This is in contrast to the flowers of most other Rubiaceae, in which the tubular corolla is longer than the corolla lobes. Also, the description by Payer, a French 19th century pioneer of floral ontogenetic research, of the floral development in Asperula, Galium, and Rubia deviates from recent insights about the development of tubular corollas, which are based on investigations of flowers of tropical Rubiaceae. Tubular corollas are currently considered as resulting from the development of underlying annular intercalary meristems, whereas Payer explained the tubular corollas in the three taxa by postgenital fusion. We therefore tested both hypotheses in six Rubieae genera, including the three taxa studied by Payer.Methods – Floral ontogeny of ten species in six Rubieae genera ba...
The taxonomy, pollination mechanism, distribution, ecology and cultivation requirements of Duperrea pavettifolia (Rubiaceae), a native of tropical continential Asia, are discussed; there is a full description of the species, accompanied...
moreThe taxonomy, pollination mechanism, distribution, ecology and cultivation requirements of Duperrea pavettifolia (Rubiaceae), a native of tropical continential Asia, are discussed; there is a full description of the species, accompanied by a colour plate and other illustrations.
Rapidly evolving and non-coding chloroplast DNA has recently been shown to contain high levels of phylogenetic structure that allows inferring well resolved and statistically supported phylogenetic trees for relationships as deep as the...
moreRapidly evolving and non-coding chloroplast DNA has recently been shown to contain high levels of phylogenetic structure that allows inferring well resolved and statistically supported phylogenetic trees for relationships as deep as the major lineages of angiosperms. These ...
Background – Vegetative and fruit characters of the Amazonian genus Dialypetalanthus point to a position in Rubiaceae. However, its floral morphology is so deviant that the genus was often placed in a family of its own. Even relationships...
moreBackground – Vegetative and fruit characters of the Amazonian genus Dialypetalanthus point to a position in Rubiaceae. However, its floral morphology is so deviant that the genus was often placed in a family of its own. Even relationships outside Gentianales were postulated. Current molecular phylogenetic studies firmly show that Dialypetalanthus belongs to Rubiaceae. Aims – This study aims to understand the idiosyncratic floral morphology in Dialypetalanthus and to compare it with the floral development in two other Condamineeae genera as well as in other Rubiaceae for which ontogenetic data are available. Material and methods – SEM and LM based floral ontogeny in Dialypetalanthus fuscescens, Mussaendopsis beccariana, and Pogonopus exsertus. Results and main conclusions – Flowers in Dialypetalanthus develop a stamen-corolla-calyx tube, which can be considered as a floral morphological link between the genus and the other Rubiaceae. The polyandrous androecium originates from an annu...
Abstract: Mantalania longipedunculata De Block & AP Davis (Rubiaceae), was recently described from Île Sainte Marie, Madagascar, based on a single collection in fruit. Due to the large-scale destruction of native forest on Île Sainte...
moreAbstract: Mantalania longipedunculata De Block & AP Davis (Rubiaceae), was recently described from Île Sainte Marie, Madagascar, based on a single collection in fruit. Due to the large-scale destruction of native forest on Île Sainte Marie, the species was suspected of ...
The genus Craterispermum (Craterispermeae, Rubiaceae) is distributed in the tropical rain forests of Africa and Madagascar, with one morphologically variable species (Craterispermum microdon) hitherto recognized in the Seychelles...
moreThe genus Craterispermum (Craterispermeae, Rubiaceae) is distributed in the tropical rain forests of Africa and Madagascar, with one morphologically variable species (Craterispermum microdon) hitherto recognized in the Seychelles Archipelago. We conducted a Bayesian analysis of the combined ETS and ITS sequence data to: 1) test the monophyly of the Seychellois species of Craterispermum; and 2) assess the phylogenetic relationships between the island populations. Our analyses supported the monophyly and, therefore, the single Malagasy origin of the Seychellois Craterispermum. The phylogenetic relationships between the three island populations were unresolved, since the Seychellois plants display a very low level of molecular variation. However, both herbarium and field studies revealed that the Craterispermum taxa occurring on the islands of Mahe, Praslin, and Silhouette, are morphologically distinct and geographically separated. As a result of these studies, two new species, Crateri...
The western Indian Ocean genus Paracephaelis is revised. Sixteen species are endemic to Madagascar, 12 of which are new for science: P. aristata sp. nov., P. bardotiae sp. nov., P. capitulifera sp. nov., P. gautieri sp. nov.,...
moreThe western Indian Ocean genus Paracephaelis is revised. Sixteen species are endemic to Madagascar, 12 of which are new for science: P. aristata sp. nov., P. bardotiae sp. nov., P. capitulifera sp. nov., P. gautieri sp. nov., P. grandifructa sp. nov., P. longipedicellata sp. nov., P. orientalis sp. nov., P. pauciflora sp. nov., P. ranirisonii sp. nov., P. russata sp. nov., P. sambavensis sp. nov., and P. seyrigii sp. nov. Paracephaelis trichantha occurs on the east coast of continental Africa and on the islands of the Aldabra Group. One other species is newly described from the Comoros, P. comorensis sp. nov. Paracephaelis is characterized by sessile inflorescences, pubescent inflorescence and flower parts, ovules arranged at the periphery of the placenta, laterally flattened seeds with entire endosperm and a shallow elongate hilum, and pollen with supratectal elements. Of the Malagasy endemics, five species are assessed as Critically Endangered with P. sambavensis sp. nov. possibly...
FIGURE 3. Ixora quadrilocularis. A—flowering branch; B—pedicel, bracteoles, ovary and calyx; C—corolla, stamens, style and 4- lobed stigma; D—adaxial view of seed. Drawn by Roger Lala Andriamiarisoa (A–C) and Antonio Fernandez (D). Based...
moreFIGURE 3. Ixora quadrilocularis. A—flowering branch; B—pedicel, bracteoles, ovary and calyx; C—corolla, stamens, style and 4- lobed stigma; D—adaxial view of seed. Drawn by Roger Lala Andriamiarisoa (A–C) and Antonio Fernandez (D). Based on Capuron 23803-SF (A–C) and coll. ignot. 13688-SF (D).
FIGURE 5. Distribution maps of the multilocular Ixora species in Madagascar. A—Ixora homolleae; B—Ixora lagenifructa; C— Ixora quadrilocularis; D—Ixora trimera.
Fig. 4. Homollea perrieri Arènes. A. Fruiting branch. B. Stipules. C. Ovary and calyx. D. Fruit. Drawn by Mr. A. Fernandez. A, C–D from Afzelius 259 (P); B from Perrier de la Bâthie 3633 (P).
Fig. 3. Homollea longiflora Arènes. A. Flowering branch. B. Stipules. C. Ovary and calyx. D. Corolla, stamens, style and stigma. E. Placenta with ovules, abaxial view. F. Placenta with ovules, adaxial view. G. Fruit. H. Transverse section...
moreFig. 3. Homollea longiflora Arènes. A. Flowering branch. B. Stipules. C. Ovary and calyx. D. Corolla, stamens, style and stigma. E. Placenta with ovules, abaxial view. F. Placenta with ovules, adaxial view. G. Fruit. H. Transverse section through fruit. I. Seed, lateral view. J. Seed, adaxial view. Drawn by Mr. A. Fernandez. A, C–D from Saboureau 7 (P); B, H–J from De Block et al. 2341 (BR); E–F from De Block et al. 768 (BR); G from Dorr & Koenders 3017 (MO).
Fig. 1. Homollea furtiva De Block sp. nov. A. Fruiting branch. B. Stipule. C. First order bract. D. Ovary and calyx. E. Detail of D showing the sparsely ciliate base of the calyx lobes. F. fruit. Drawn by Mr. A. Fernandez. From...
moreFig. 1. Homollea furtiva De Block sp. nov. A. Fruiting branch. B. Stipule. C. First order bract. D. Ovary and calyx. E. Detail of D showing the sparsely ciliate base of the calyx lobes. F. fruit. Drawn by Mr. A. Fernandez. From Razafitsalama et al. 583 (MO).
© 2015 Botanic Garden Meise and Royal Botanical Society of Belgium. Background and aims - In Rubiaceae, most flowers have a tubular corolla. Earlier studies showed that a tubular corolla may develop from an annular primordium or result...
more© 2015 Botanic Garden Meise and Royal Botanical Society of Belgium. Background and aims - In Rubiaceae, most flowers have a tubular corolla. Earlier studies showed that a tubular corolla may develop from an annular primordium or result from postgenital fusion of petals. Often stamen-corolla tubes are formed, concurring with epipetaly. Moreover, flowers with a fenestrated tubular corolla occur. The scattered distribution of species with corolla splits in Rubiaceae suggests a multiple origin. We intended to answer the following questions: (1) should the tubular corollas studied be assigned to a single or to several character states?; and (2) are the corolla splits studied homologous? We investigated the corolla development in five species of the Spermacoceae alliance with corolla splits in comparison with a Spermacoce species without. Methods - Floral developmental studies using scanning electron microscopy (SEM) and light microscopy (LM). Results - In Spermacoce, the tubular corolla with epipetalous stamens originates from an annular primordium. In Sacosperma and Pentas, the tubular corolla develops similarly with the stamens fixed basally. In Paederia and Pentodon, individual petal primordia originate on a ring wall. Next, stamen primordia appear adaxially on the ring wall. Then, the bases of the petals fuse partially, resulting in fenestrated tubular corollas. In Sacosperma and Pentas, corolla splits are actively formed in an initially closed tubular corolla. Conclusions - The tubular corollas of the species studied in Spermacoce, Sacosperma and Pentas are early sympetalous. Those in Paederia and Pentodon are late sympetalous. The tubular corolla results from a combination of three developmental processes: the formation of (1) a stamen-corolla tube, (2) a corolla tube sensu stricto, and (3) postgenital fusion of petals. The final form of the tubular corolla and the stamen insertion depend on the relative activity of these processes. Consequently, similar looking tubular corollas may constitute different character states. The corolla splits studied constitute two different cryptic character states in respectively Sacosperma/Pentas and Paederia/Pentodon.status: publishe
... Ribbed fruits do not occur in other species within Pavetteae, although fruits sometimes seem weakly ribbed when dry because the vascular bundles stand out from the dried fruit wall (eg,Robbrechtia De Block, Homolliella Arènes). The...
more... Ribbed fruits do not occur in other species within Pavetteae, although fruits sometimes seem weakly ribbed when dry because the vascular bundles stand out from the dried fruit wall (eg,Robbrechtia De Block, Homolliella Arènes). The function of the ribs is unknown. ...