Early flowers of primuloid Ericales from the Late Cretaceous of Portugal and their ecological and phytogeographic implications

A distinctive feature of the major eudicot diversification that occurred through the Late Cretaceous is the unequivocal presence of Cornales and diverse Ericales. Here we describe well-preserved fossil flowers from the Mira locality in western Portugal, of Campanian-Maastrichtian age, that we assign to a new extinct genus of Ericales with two new species; Miranthus elegans gen. et sp. nov. and Miranthus kvacekii sp. nov. The fossil flowers are pedicellate, structurally bisexual, actinomorphic, pentamerous and isomerous, with five narrowly triangular persistent calyx lobes, a five-lobed corolla, five antepetalous stamens, five staminodes alternating with the petals and a semi-inferior, unilocular ovary. The ovary consists of five carpels and has a raised nectariferous ring with stomata-like openings above the insertion of the perianth, and a long five-angled style. A key feature, which confirms a relationship with Primulaceae s. l., is the free, central dome-shaped placenta that bears numerous, densely spaced ovules. The ovary matures into a capsule containing many, minute, reticulate seeds. Flowers of Miranthus are especially similar to those of extant Samolus, a genus of about twelve species that is sister group to other genera of subfamily Theophrastoideae and that has a disjunct distribution mainly in the Southern Hemisphere. Miranthus also appears to have grown in environments influenced by marine conditions, an ecological preference also seen in Samolus. Miranthus expands the diversity of Ericales known from the Late Cretaceous, and together with previously described fossils provides further evidence that the diversification of Ericales was already underway by the Campanian-Maastrichtian stages of the Late Cretaceous.

Persistent Calyxes in Postbloom Fruit Drop: A Microscopy and Microanalysis Perspective

Citrus postbloom fruit drop, caused by Colletotrichum spp., is an important disease in the Americas. The pathogen infects citrus flowers, produces orange-brown lesions on petals, and may cause the abscission of young fruit. In diseased flowers, the calyxes remain attached to the peduncle after the young fruit drop. No anatomical and microanalysis studies have been conducted to determine whether calyx tissues can be infected by Colletotrichum spp. and why calyxes remain attached to the peduncle. Based on light microscopy, we demonstrate that the ovary abscission zone exhibits a separation region composed of layers of thickened lignified walled cells, indicating that abscission involves the disruption of cell walls. The first layers of the protective zone (PZ) are composed of densely packed cells with suberized walls produced by the wound meristem. Beneath the PZ, there is a compact mass of small cells that accumulate starch grains. X-ray fluorescence microanalysis (µ-XRF) confirmed the increased accumulation of calcium in the receptacle of the persistent calyxes compared to non-inoculated citrus flowers. Moreover, the peduncle pith and the receptacle exhibit hypertrophied cells with thick walls that may be related to calyx retention. Fungal structures are not observed inside the persistent calyx tissues.

Miconia bahiana (Melastomataceae, Miconieae), a new species from semideciduous forest in Bahia, Brazil

Background – Recent collection efforts in semideciduous forests from Bahia, Brazil, provided material that belongs to a species of Miconia (Melastomataceae) not yet described scientifically. Here, we describe this new species and compare it to four species in the “Miconia discolor group” that share morphological similarities. We also provide illustrations, photographs, a distribution map and conservation assessment for the new species.Methods – This study was based on specimens from several herbaria and field collections, which resulted in photographs and ethanol-preserved material, as well as information about the environment where the plants were found. The conservation assessment is based on field observations and spatial analyses (i.e., extent of occurrence, area of occupancy), following IUCN guidelines and criteria.Results – Miconia bahiana has been collected ten times in four localities since 2001, ranging from 800 to 1041 m elevation. The species resembles a group of species endemic to the Brazilian Atlantic Forest (M. capixaba R.Goldenb., M. cubatanensis Hoehne and M. setosociliata Cogn.), all of them with abaxial leaf surfaces densely (seldom moderately) covered with branched trichomes, inflorescences with paraclades with a first dichasial branching, then uniparous (scorpioid) branchings, and white, glabrous stamens lacking appendages or with dorsal ones, the anthers with a moderate to large pore. It differs from the above cited species by the rounded to subcordate leaf bases, and the persistent calyx with a truncate inner membrane, lacking well-defined lobes. This new species is described, illustrated, and compared with the species mentioned above. According to IUCN guidelines and criteria, we recommend to assess M. bahiana as Endangered (EN).

Miconia lucenae (Melastomataceae), a new species from montane Atlantic Forest in Espírito Santo, Brazil

We describe Miconia lucenae R.Goldenb. & Michelang., a new species from the montane Atlantic Forest in Santa Teresa in the state of Espírito Santo. Our analysis, based on three plastid spacers (atpF-atpH, psbK-psbl and trnS-trnG), one plastid gene (ndhF, not available for M. lucenae), and two nuclear ribosomal loci (nrITS and nrETS), showed that it belongs to a small clade with Miconia paradoxa (Mart. ex DC.) Triana (Minas Gerais) and M. michelangeliana R.Goldenb. & L.Kollmann (Espírito Santo). The three species in the “Paradoxa clade” can be recognized by the plants with glabrous or glabrescent branches and leaves, white petals and yellow stamens, these with the connectives not prolonged below the thecae, ventrally unappendaged, dorsally unappendaged or with a minute tooth, the latter bilobed or not, glabrous ovary, and the fruits with a persistent calyx. Miconia lucenae can be recognized, among the species in this clade, by the shrubby plants with terete young branches, short inflorescences, usually with red axes, and the 2-bracteolate, sessile, 4-merous flowers, with a ciliolate inner portion of the sepals, lanceolate petals, and 4-celled ovaries. This species can be considered as endangered according to IUCN criteria.

A new species of Syzygium (Myrtaceae) from the Agasthyamalai Biosphere Reserve, Kerala, India

Syzygium ponmudianum, a new tree species from Ponmudi, Agasthyamalai Biosphere Reserve, Kerala, India is described. This species is closely allied to Syzygium benthamianum and S. myhendrae but differs from it by having a reddish brown coloured cylindrical stem, large sized leaves with 22-29 pairs of secondary veins, deltoid and persistent calyx lobes, pyriform hypanthium, variously statured filaments, deep purple berries with ovate seeds.

Notes on taxonomic identity and typification of Fagraea coromandelina (Gentianaceae)

The genus Fagraea Thunberg (1782: 132), belonging to the family Gentianaceae, is represented by 70 species in the world (Struwe et al. 2002). It is distributed in India, Sri Lanka, Sumatra, Malay Peninsula, Borneo, New Guinea, French Polynesia, China, Philippines and Australia. Clarke (1885) reported 5 species from the present political boundary of India, of which 2 species were recorded by Gamble (1921) from South India. The genus includes glabrous epiphytic trees or shrubs, with simple, opposite and coriaceous leaves, fragrant flowers and pulpy berries with a persistent calyx.

Early Eudicot flower and fruit: Dakotanthus gen. nov. from the Cretaceous Dakota Formation of Kansas and Nebraska, USA

An extinct plant that populated the eastern margin of the Cretaceous Midcontinental Seaway of North America about 100 million years ago has attracted interest as one of the earliest known bisexual flowers in the fossil record. Reexamination of the type specimen of Carpites cordiformis Lesq., and corresponding specimens from sandstones and clays of the Dakota Formation of Kansas and Nebraska and the correlative Woodbine Sandstone of Texas, with both light microscopy and micro CT scanning, leads to a revised concept of the morphology and affinities of the “Rose Creek flower”. The moderately large flowers (22–30 mm diameter) have two perianth whorls: five basally fused sepals and five free spatulate petals. The gynoecium is pentacarpellate with five styles. A crescent-shaped nectariferous pad occurs at the base of the gynoecium aligned with each sepal. Ten stamens are inserted at the level of the nectaries, one whorl organized opposite the sepals and another opposite the petals. In situ pollen is oblate, brevitricolporate and finely verrucate. The fruits are loculicidal capsules with persistent calyx and disk. Comparing the full suite of observed characters with those of extant angiosperms indicates particularly close similarity to the monogeneric fabalean family Quillajaceae, with shared features of perianth number and morphology, nectary position and morphology, stamen number and morphology, and gynoecium merosity, although the fossil differs from extant Quillaja in fruit type (capsule vs basally syncarpous follicles) and especially in pollen morphology (10 μm oblate, microverrucate, vs 30–40 μm prolate, striate).

Styrax rhytidocarpus (Styracaceae), a new species from Hunan, China

A new species, Styrax rhytidocarpus W. Yang & X. L. Yu (Styracaceae) from Hunan, China, is described and illustrated. This species can be readily distinguished from all other species of Styrax by the combination of characters: glabrous peduncles, bracteoles, and pedicels; 1.7–2.0 × 0.8–1.3 cm corolla lobes; bowl-shaped and deeply rugose persistent calyx; thick, fleshy, and rugose fruit with slightly curved and long-rostrate apex; and ridged and densely stellate-hairy seeds.