Involucral Bracts Research Articles

Leontopodium nyingchiense (Asteraceae), a new species from Xizang (Tibet), China

Leontopodium nyingchiense, a new species of Asteraceae from the Xizang (Tibet) Autonomous Region of China, is described and illustrated here. Morphologically, it is most similar to L. lingianum but can be distinguished by the combination of monoecious and dioecious individuals, involucral bracts arranged in 3–5 series (with outer series herbaceous and middle to inner series membranous), fimbriate apices on female florets, rough-edged lobes on male florets, and achenes lacking costae. Phylogenetic analyses further support the separation of this new species from related taxa. Finally, we characterize this new species through both morphological comparisons and molecular analyses.

Half a century later, a new species of Wunderlichia (Wunderlichieae, Asteraceae) from the Atlantic Forest inselbergs of Espírito Santo, Brazil

Wunderlichia capixaba, a new species of the tribe Wunderlichieae, Asteraceae family, is described, discussed, and illustrated. The species is currently only found in Pedra dos Cabritos in the community of Barra Alegre, municipality of Castelo, Espírito Santo state, Brazil. It has been categorized as critically endangered. Morphologically akin to W. insignis, W. capixaba distinguishes itself through its synanthous habit (maintaining leaves throughout the flowering period), green involucral bracts (in vivo), dark brown when dried (in sicco), an erect peduncle, approximately 60 florets per capitulum, a nectary longer than wide, and a 3-seriate pappus.

Inter-archipelago dispersal, anagenetic evolution, and the origin of a rare, enigmatic plant genus on a remote oceanic archipelago.

Island plants have long interested biologists because of their distinctive morphological features and their isolation on small land areas in vast oceans. Studies of insular endemics may include identifying their ancestors, tracing their dispersal to islands, and describing their evolution on islands, including characters adaptive to island life. Thamnoseris is a monospecific genus endemic to the Desventuradas Islands, Chile. Its origins and relationships are unresolved, given the challenges of getting to the islands and accessing plants there. Sequences from ITS of nrDNA and the complete chloroplast genome were employed to resolve phylogenetic relationships of Thamnoseris. Phylogenetic analyses of nuclear and chloroplast sequences showed Thamnoseris nested within or sister to Dendroseris, the largest endemic genus in the Juan Fernández Islands. Thamnoseris evolved from a common ancestor of all or most species of Dendroseris prior to the diversification of Dendroseris in the Juan Fernández archipelago. The ancestor of Thamnoseris dispersed to the Desventuradas archipelago, which consists of the islands San Ambrosio and San Félix, within the past 3 Ma (the age of San Ambrosio). This is the only known example of possible plant dispersa\l between the Juan Fernández and Desventuradas Islands. We also mention two less likely biogeographic scenarios for the origin of Thamnoseris, which has features not seen in Dendroseris: small capitula with yellow florets; style branches barely divergent; and basally swollen subtending involucral bracts, all features associated with selfing and reduced dispersal. Goats and rabbits (now removed) reduced T. lacerata, once very abundant on the Desventuradas Islands, to several plants, making it of extreme conservation concern and worthy of further study.

A New Species of <I>Lactuca</I> (Asteraceae) from Himachal Pradesh, India

During the course of a revisionary study on the subtribe Lactuceae in India, the authors encountered some specimens which showed affinities with Lactuca rapuncubides Clarke in the general habit of plant, shape of upper and lower leaves, in the drooping nature of the inflorescence and in having outer involucral bracts much shorter than the inner. Critical examination of these specimens both at BSD and DD, particularly the achene character and the involucre, proved that these specimens belong to a new species, which is described here.

Litsea vagamonica (Lauraceae): a new species from southern Western Ghats, Kerala, India

A new species in the family Lauraceae, Litsea vagamonica is described and illustrated from the Vagamon Hills, Kerala, India. The new species is similar to Litsea wightiana, from which it differs by its glabrous branchlets, thinly coriaceous leaves, glabrous on both surfaces, with acute to acuminate apex, glabrous petioles, densely puberulent brachyblasts, fulvous-tomentose involucral bracts, the inner ones with 6-nerves, stamens with stipitate glands, presence of a pistillode in male flowers, an ellipsoid, sparsely pubescent ovary in female flowers, and an ellipsoid fruit with puberulent fruit cupule on a glabrous, 0.9–1.2 cm long pedicel.

New Record of Two Medicinal Plants, Exallage Auricularia and Gomphostemma Ovatum, from Ultapani Reserve Forest, Northeast India

Aim: This report discusses two medicinal plants, namely Exallage auricularia (L.) Bremek from Rubiaceae family and Gomphostemma ovatum Wall from Lamiaceae family from Ultapani Reserve Forest of Bodoland Territorial Region (BTR) of Assam, India, are recorded, described, and identified based on their morphological characters, taxonomical notes, phenology, and field photos along with map of distribution. Methods: The local Bodo-trib of Assam used leaf paste of E. auricularia to cure jaundice and piles and G. ovatum for treatment of different ailments like flu, cough, cold, skin irritations, symptoms of indigestion, jaundice, etc. Results: Inflorescence - verticillaster inflorescence in leaf axil, 3 to many flowers, 2 to 5 cm long. Flowers are born in opposite cymes, subtended by bracts, easily indistinguishable from leaves, and the arrangement of flowers is congested or lax. Bracts - leaf-like small cluster, subtending cyme, involucral bracts, stellate hairs, large bracteoles exceeding the calyx. Conclusion: G. ovatum is a perennial plant that can grow up to around 1.5 m tall and has tuber-like roots with infrequent node-level rooting.

Two new and endangered species of Paepalanthus sect. Diphyomene (Eriocaulaceae) from the Brazilian Cerrado

Two new species of Paepalanthus (Eriocaulaceae) from the Cerrado hotspot in central Brazil are described and illustrated. Paepalanthus avacanoeiro Trovó & R. Silva-Oliveira sp. nov. occurs in the Chapada dos Veadeiros region, growing on quartzite rocky soils. The species is similar to P. urbanianus, distinguished mainly by being a more robust species with pilose and patent leaves with blackish base and ciliated margin, by its reproductive axis covered by remotely disposed bracts with acuminate apex, and by its inflorescence with fewer scapes. It is currently known from two subpopulations occurring just outside of the local conservation units and is assessed as Critically Endangered (CR). Paepalanthus burle-marxii Trovó sp. nov. is distributed in the vicinities of Brasília, Pirenópolis, Luziânia, and Santo Antônio do Descoberto. It is known from many historical and recent collections inhabiting typical open grasslands, usually over argillaceous-rocky soils. It is distinguished from P. linearis, its most similar species, by its glabrous and wider leaves with membranaceous margin, its narrower capitula with few flowers and dark castaneous involucral bracts, and by the pilosity of the pistillate flower sepals. It is assessed as Vulnerable (VU). Line drawings, photos taken in the field, distribution maps, and comments are provided alongside its conservation status and IUCN red list categories.

A nomenclatural and taxonomic re-evaluation of neglected Centaurea candelabrum Hayek & Kosanin (sect. Acrocentron, Asteraceae) and related serpentine endemics from the Balkan Peninsula

Centaurea sect. Acrocentron comprises several taxonomically intricate groups of taxa, including the Balkan endemic obligate serpentinophytes: C. melanocephala, C. candelabrum and C. albertii. Despite its distinctive morphological characteristics, C. candelabrum was considered conspecific with C. melanocephala. A similar situation pertains to C. albertii, which has largely been considered a synonym of C. melanocephala. Considering that several recent floristic works treat these taxa as separate species distributed in different serpentinite areas of the Balkans, the main objectives of our study were to analyse the taxonomic and chorological relationships between them, and to propose a new taxonomic concept. Our study was based on an extensive revision of herbarium material, including the type specimens, personal field data and observations of living plants. Our comprehensive study showed that the plants previously recognised as C. melanocephala from the Stolovi mountain in central Serbia and those previously recognised as C. candelabrum from northern Albania deserve the rank of distinct species. These species can be easily distinguished from each other by a number of characters, including their general habitus, the dimensions and shape of the basal leaves, and the indumentum of the involucral bracts. Given the only slight differences observed between the populations in Kosovo and Albania, the question of whether C. albertii is conspecific with C. candelabrum or deserves an independent taxonomic status remains unresolved until further detailed integrative studies are conducted. In view of the clear differences in morphological and ecological characteristics which exist within this group compared to other representatives of sect. Acrocentron, we propose the separation of the studied taxa into a separate C. melanocephala complex, as outlined in this paper.

Prunus quanzhouensis: a newly discovered species of Prunus subgen. Cerasus (Rosaceae) from northeastern Guangxi, China

Prunus quanzhouensis is a new species of Rosaceae discovered in Guangxi, China, which is here described and illustrated. Despite its morphological similarities to P. campanulata, P. conradinae and P. xueluoensis, it can be distinguished from them by being shrubs or small trees, with 1.5–3.0 m tall, leaves with 10–13 pairs of lateral veins, abaxially glabrous involucral bracts, adaxially appressed villous bracts, flowers measuring 1–1.2 cm in diameter, tubular hypanthium with about 9×3 mm, oblique sepals, 30–35 stamens, and a style that is villous and longer than the stamens. Less than six populations of this new species have been found in the type locality, with approximately 130 mature individuals, which accounted for more than 95% of the total population. Based on direct observation in the field and the IUCN Red List Categories and Criteria, P. quanzhouensis is classified as Endangered (EN).

Artemisiaqingheensis (Asteraceae, Anthemideae), a new species from Xinjiang, China.

Artemisiaqingheensis (Asteraceae, Anthemideae), a new species from Qinghe County, Xinjiang, China, is described and illustrated. We investigated its phylogenetic position and relationships with 35 other species of Artemisia using whole chloroplast DNA sequence data. The molecular phylogenetic results and morphological evidence (multi-layered involucral bracts and homogamous capitula with bisexual flowers) showed that the new species belongs to ArtemisiasubgenusSeriphidium. A diagnostic table and discussion of morphological characters are provided to distinguish the new species from A.amoena, A.gracilescens, A.lessingiana and A.terrae-albae.

Five New Combinations in Passiflora sect. Dysosmia (Passifloraceae)

Five taxa, originally described or typically circumscribed as varieties of Passiflora foetida L. (Passifloraceae), are here recognized as distinct species in Passiflora sect. Dysosmia DC. on the basis of their unique suites of morphological traits that include variations in the arrangement of foliar glands, reduced involucral bracts, distinct vestiture, and, in most cases, red fruit. Four new combinations and one nomen novum are published for these: P. lanuginosa (Killip) H. T. Svoboda, P. oaxacana (Killip) H. T. Svoboda, P. orinocensis (Killip) H. T. Svoboda, P. subintegra (Killip) H. T. Svoboda, and P. wrightiana H. T. Svoboda. The last is a replacement name for P. ciliata Aiton var. riparia C. Wright ex Griseb. Their distributions and distinctions from P. foetida are summarized.

Morphological characterization of germplasm accessions of safflower (Carthamus tinctorius L.)

The present investigation was conducted at Research cum Instructional farm of Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh during rabi, 2019-20. The experimental material included 108 germplasm accessions and 4 checks (A-1, PBNS-12, CG Kusum-1 and IGKV Kusum) obtained from Germplasm Maintenance Unit (GMU), Indian Institute of Oilseed Research (IIOR), Hyderabad. In the experiment, the selected germplasm accessions were evaluated for 26 morphological characters in an augmented design to determine distinctiveness among the accessions. Observations were recorded at different growth stages of based on the DUS descriptors forsafflower assuggested by IIOR, Hyderabad. First leaf: length of blade, first leaf:width of blade, petal: colour, petal: change in colour (faded stage), leaf: width of blade, leaf:shape, capitulum: width of outer involucral bract of maincapitula (cm), capitulum: ratio length/width of outer involucral bract of main capitulum (cm), capitulum: number of spines on outer involucral bract of main capitulum, capitulum: diameter of main capitula (cm), plant: length oflongest primary branch (cm), seed: hull content (%) were exhibited highest variation among the germplasm accessions. Genotypes which were unique for a particular character can be used as reference varieties in furtherDUS characterization experiments.

Quercus castaneifolia subsp. Recurvatus (fagaceae) a new Subspecies from Hyrcanian Forests, North of Iran

During the study on flora of Hyrcanian forests and collecting specimens in order to plant in Hyrcanian habitat of National Botanical Garden of Iran, among the collected specimens, some specimens of the Quercus castaneifolia (Chestnut leaved oak) from south of Sari city in Mazandaran Province in North of Iran seemed to be interesting and were different from the other known subspecies of Q. castaneifolia. Results of morphological study of the species showed that there are clear differences between shape of the cupule and some micro-morphology traits of the leaf trichomes and pollen. Thus, based on the botanical traits of the new taxon and according to summarised data from the obtained results of the other subspecies and variety of the Q. castaneifolia, this taxon was identified as a new subspecies and named: Quercus castaneifolia subsp. recurvatus Zare et Panahi which is described here. The new taxon is related to Quercus castaneifolia subsp. castaneifolia var. castaneifolia and well characterised by having different shape and arrangement of the involucral bracts on the acorn cupule comparing with the others.

Fruit Structure in Amphicarpic Annual Gymnarrhena micrantha (Asteraceae, Gymnarrheneae) in Relation to the Species Biology

In the amphicarpic annual Gymnarrhena micrantha Desf. (Asteraceae), aerial and subterranean fruits differ in morphology, dispersal ability and germination behavior. The aim of our work was to study their structural features in relation to the eco-physiological properties, using light and scanning electron microscopes. Five fruit morphs were found, three of aerial achenes: ebracteate, bracteate and double bracteate ones, and two subterranean fruits with achenes, enveloped in involucral bracts, developed from (I) sessile or (II) not sessile different heads. This species shows divergent fruit differentiation, an increase in their diversity along several lines of morphological differentiation, which corresponds to a multiple seed dispersal and germination strategy. In addition to the already known distinctive features of subterranean achenes (larger size, undeveloped pappus, poor pubescence), they also differ in the simplified structure of the apical and basal achene regions, the absence of the corolla expanded base (cupula) and nectary, other cells parameters in the exotesta and endosperm, another form of the disproportionately developed embryo. The peculiarities of probably subterranean fruit II (seemingly originated through apomixis) extend to various color, pappus structure, sparse pubescence, and the ability of the fruit wall to delaminate. The lack of dense pubescence in the subterranean achenes is a key trait that could lead to increased water permeability of the fruit wall and affect germination rate. Possible adaptive significance of aerial achene structural features is discussed, including specialized corolla cupula, which may be an adaptation to dissemination by rainwater and ants.

HbNST1 is a positive regulator of the lignin accumulation in strawflower bracts

Strawflower (Helichrysum bracteatum) capitula have papery bracts and thus have the qualities of a naturally dried flower. The involucral bract cells have a secondary cell wall (SCW) of which a crucial component is lignin. Although the constituents of SCWs have been studied extensively in plants, little is known of the mechanism regulating SCW formation, especially lignin biosynthesis in the involucral bracts of strawflower. In this study, a homolog of NAC SECONDARY WALL THICKENING PROMOTING FACTOR 1, designated HbNST1, was identified as a positive regulator of lignin biosynthesis in strawflower. The transcript level of HbNST1 was the highest in the involucral bracts. Subcellular localization analysis indicated that HbNST1 was localized to the nucleus. Overexpression of HbNST1 in Chrysanthemum indicum promoted the expression of a gene related to lignin biosynthesis, a homolog of cinnamyl alcohol dehydrogenase, designated CiCAD, suggesting that HbNST1 was associated with the accumulation of lignin in the SCW of the involucral bracts. Taken together, the results suggested that HbNST1 positively regulated lignin accumulation in the involucral bracts and mediated the expression of lignin biosynthesis-related genes in strawflower.

Borreria savannicola (Spermacoceae, Rubiaceae), a new species from savanna patches within the Caatinga, Ceará State, Brazil

A new species of Borreria from savanna vegetation found within the Caatinga in northwestern Ceará, Brazil, is described and illustrated. Borreria savannicola has an affinity with B. scabiosoides, sharing with it the habitat preference and similar morphological characteristics such as corolla infundibuliform, stigma bilobed and shape of seeds. Nevertheless, the new species differs mainly in its erect habit, linear leaves, terminal glomerule with up to 10 involucral bracts, and obovoid capsule. Images of anatomical characters, electro microphotography of flower, fruit, seed, and pollen, together with photographs of the habitat, distribution map and conservation status are provided.

Cyperus zikae, a New Species of Cyperus sect. Incurvi (Cyperaceae) from Venezuela

Cyperus zikae G. C. Tucker is described as a new species of Cyperus sect. Incurvi Kük. It is known from a single collection from the lowlands of southern Venezuela. Based on morphology, it is most closely related to C. grandi-simplex C. B. Clarke (eastern Brazil), from which it differs in scabrid culms, papillate involucral bracts, lanceolate-deltate floral scales with scabrid apex, one stamen per flower, longer stigmas, and papillate achenes.

A taxonomic revision of the genus Callilepis DC. (Asteraceae) in South Africa.

A complete revision of the genus Callilepis is presented. Most specimens in herbaria are identified either as C. leptophylla or C. laureola because of misconceptions about the other previously described species. A key to all the taxa is provided, full descriptions of all the taxa drawn up and distribution maps given. Two new species (C. nepotiana and C. retiefiae) and one new variety (C. hispida var. paucicephala) are described. The two names C. glabra and C. hispida are re-instated while C. laureola is reduced to a synonym under C. hispida. The names C. glabra and C. laureola are lectotipified. The monotypic genus Zoutpansbergia is included in Callilepis. The genus description is emended to include information of the taxa with corymbose synflorescences and imbricate involucral bracts.

Molecular insights on the conflicting generic boundaries in the Carduncellus‐Carthamus complex (Compositae)

AbstractThe Carthamus‐Carduncellus complex is formed by approximately 50 taxa that are widely distributed throughout the Mediterranean basin and western Asia. The generic delineation of this complex has always been controversial. Currently, there are three widely diverging taxonomical proposals, suggesting that the complex is formed by (1) a single genus, Carthamus; (2) two genera, Carduncellus and Carthamus; and (3) four genera, Carduncellus, Carthamus, Femeniasia, and Phonus. The generic classification has varied depending on the importance assigned to some morphological characters, i.e., the morphology/structure of pappus, achenes, and involucral bracts. All these generic changes have complicated the nomenclature of the complex, leading to species wandering between four different genera. To objectively assess the taxonomic delimitation of this complex, we carried out phylogenetic analyses using nuclear (external and internal transcribed spacers of rDNA) and plastid (ndhF, trnH, rpl32, trnT) data, as well as multispecies coalescent model analyses on near‐complete sampling. Phylogenetic reconstructions resolved two monophyletic groups, Carthamus s.str. and Carduncellus s.l. Within the latter, some groups could be differentiated, such as the monophyletic genus Phonus and the monospecific Femeniasia. Our multispecies coalescent analyses strongly support a classification based on four genera in the complex Carthamus‐Carduncellus. In contrast, classifications based on only one or two genera lack relevant support. However, the absence of synapomorphic morphological characters that define the Carduncellus lineage (Carduncellus, Phonus, Femeniasia), and the possible hybridization in the ancestral lineages detected by incongruences between plastid and nuclear markers make it difficult to define clear generic boundaries. We propose maintaining the hypothesis of four genera, which was the first classification supported by molecular evidence, pending a broader study (both molecular and morphological) to reach a more definitive delineation and avoid more unfounded generic changes.

Additional fossil specimens of Eophylica (Rhamnaceae) in mid-Cretaceous amber from the Hukawng Valley, Myanmar

The recently described fossil angiosperm genus Eophylica (Rhamnaceae) was based on 18 amber-embedded specimens derived from two sites in northern Myanmar. A vegetatively similar fossil, which came from the same amber mines but which lacked flowers, had been previously described as a putative green alga and given the name Electrophycus. The dimensions and vegetative aspect of that taxon’s holotype specimen are identical with those of the Eophylica fossils. Four additional specimens were acquired by the senior author after the publication of Electrophycus, all of which have a single terminal flower that is either immature or essentially fully formed. Using techniques of floral dissection, high magnification microscopy, and microphotography of the better-developed flowers, we present a more detailed picture of the floral organs, especially the stamens and style, of Eophylica. These flowers differ from the holotype specimen of Eophylica and 3 of its paratypes in that they possess involucral bracts of a so-called ‘pseudanthial head,’ a structure that the authors of Eophylica had only ascribed to certain other paratype specimens of the genus.