Flower longevity and duration of pistil receptivity in high mountain plants

Flowers of high mountain plants are generally long-lived to compensate for the low frequency of pollinator visits at higher altitudes. However, nothing is known about floral plasticity when pollinators are absent because of unsuitable weather conditions. We investigated both, actual longevity of naturally pollinated flowers and potential flower longevity, the capacity to prolong corolla life-time and pistil receptivity when pollination is retarded. Seven high mountain plant species from different elevations in the European Alps were tested: Gentianella germanica, Ranunculus alpestris and Saxifraga caesia are restricted to the alpine zone, Cerastium uniflorum, Ranunculus glacialis, Saxifraga bryoides and Saxifraga moschata occur from the higher alpine to the glacier zone.     

<Emphasis Type="Italic">Chirita luochengensis</Emphasis> (Gesneriaceae), a new species from limestone areas in northern Guangxi,China

Chirita luochengensis, a new species of Gesneriaceae from Guangxi, China, is described and illustrated. The new species is similar to C. linearifolia in leaf shape, but can be distinguished by the apex of leaf blade obtuse to round, corolla purplish, 3–4.2 cm long, corolla tube 2–2.5 cm long, 10–15 mm diameter at the mouth, staminodes 3, disc ca. 2.5 mm in height, pistil 2.5–3 cm long, stigma obtrapeziform, 4 mm long, and apex shallowly 2-lobed.     

Primulina suichuanensis sp. nov. (Gesneriaceae) from Danxia landform in Jiangxi,China

Primulina suichuanensis X. L. Yu & J. J. Zhou, a new species of Gesneriaceae from Jiangxi, China, is described and illustrated. Morphologically, the new species is most similar to P. roseoalba, but differs by entire leaf blade margin, narrowly ovate bracts, reddish–purple or bluish–purple corolla, 3.0–3.4 cm long corolla tube, white filaments, and 3.6 cm long pistil. It flowers from September to November.     

Evolutionary correlation between floral monosymmetry and corolla pigmentation patterns in <Emphasis Type="Italic">Rhododendron</Emphasis>

Floral symmetry and pigmentation are features of flowers that are believed to be associated due to their shared influence on pollinator behaviour. However, the evolution of such associations has so far not been examined. We analysed variation in Rhododendron flowers, in a phylogenetic context, to test whether the evolution of floral symmetry types and pigment patterns are correlated. Variation in floral symmetry due to variation in corolla form, stamen flexion, stamen arrangement, pistil flexion, as well as corolla pigment patterns was documented in 98 species of Rhododendron. Phylogenetic relations among these species were estimated using maximum likelihood (ML) and Bayesian methods, building on a published molecular dataset of sequences of RNA Polymerase II subunit (RPB2-I). Evolution of the floral traits was studied using phylogenetic correlation tests and ancestral state reconstructions (maximum parsimony, MP and ML methods). Significant correlations were found between corolla pigment pattern and type of floral symmetry at the level of corolla form, stamen flexion or arrangement, and pistil flexion. As expected from their similar roles in enhancing attractability to pollinator, monosymmetric corollas and presence of pigment pattern are correlated; in addition, monosymmetry involving other whorls too shows such a relationship with pigment patterns, and with each other. Multiple evolutionary shifts were detected between monosymmetry and polysymmetry of floral traits in Rhododendron. The relationship between floral monosymmetry attributes and presence of corolla pigment patterns, and additionally, frequent evolutionary shifts in these traits suggest pollinator-mediated selective pressures in Rhododendron.     

Manipulus Rubiacearum IV. Kerianthera (Rubiaceae), a new genus from Amazonian Brazil

A new genus,Kerianthera, and its single new species,K. preclara, are presented.Kerianthera is a member of tribe Condamineeae and is easily distinguished from related genera by its 4-merous calyx, 7 or 8-merous corolla, stamens separating from the corolla tube at its apex, anthers with approximately 300 locelli, septicidal capsules, and seeds irregularly biwinged. It is most similar phenetically to the genusPinckneya with which it shares foliar calyx lobes on some flowers, corolla lobes densely pubescent on the inner surface, and winged seeds.     

Mentzelia canyonensis (Loasaceae), a new species endemic to the Grand Canyon, Arizona, U.S.A.

We describe Mentzelia canyonensis, a new species endemic to the Grand Canyon. Based on floral and fruit forms, shoot system architecture, and phylogenetic analyses of nuclear ribosomal DNA, we infer that M. canyonensis belongs to the ‘subshrubby’ clade of Mentzelia section Bartonia, which includes the morphologically similar M. hualapaiensis, M. oreophila, M. puberula, and M. tiehmii. The new species is most similar to M. hualapaiensis, which is also known only from the Grand Canyon. These two species share leaf shape, subshrubby habits, corolla color, and fruit shape, although they differ in staminode presence and especially in leaf and corolla size. Principal component analyses of variation among floral and vegetative traits demonstrates that M. canyonensis and M. hualapaiensis share highly overlapping floral character space, but M. canyonensis occupies unique vegetative character space compared to similar species. A dichotomous key is provided to assist with identification of, and differentiation among, species of Mentzelia section Bartonia that occur in the Grand Canyon region.     

Bulk Segregant Analysis of an Induced Floral Mutant Identifies a MIXTA-Like R2R3 MYB Controlling Nectar Guide Formation in Mimulus lewisii

The genetic and developmental basis of many ecologically important floral traits (e.g., carotenoid pigmentation, corolla tube structure, nectar volume, pistil and stamen length) remains poorly understood. Here we analyze a chemically induced floral mutant of Mimulus lewisii through bulk segregant analysis and transgenic experiments and identify a MIXTA-like R2R3 MYB gene that controls nectar guide formation in M. lewisii flowers, which involves epidermal cell development and carotenoid pigmentation.     

Hemiboea sinovietnamica sp. nov. (Gesneriaceae) from a limestone area along the boundary of Sino‐Vietnam

Hemiboea sinovietnamica W. B. Xu & X. Y. Zhuang, a new species of Gesneriaceae from a limestone area along the boundary of Sino‐Vietnam, is described and illustrated. The new species is similar to H. longgangensis Z. Y. Li with its yellowish corolla, but differs in having leaf blades glabrous on both sides, involucre trigonous, 2–3 cm in diameter, glabrous outside, glabrous cymes, a white calyx that is glabrous outside, and glabrous pistil and capsule.     

四川卧龙国家级自然保护区马先蒿属一新种——熊猫马先蒿

熊猫马先蒿(Pedicularis pandania)是在四川卧龙国家级自然保护区发现的马先蒿属一新种。该新种属于互生叶类群,其基生叶成丛,花冠属于短管有喙型,且下唇将喙包裹住,花管在近萼端发生约180度的扭旋使得花冠下唇在侧上方,这一特征明显区别于其他国产马先蒿物种。分子系统发育分析结果表明,熊猫马先蒿是Clade 7 成员,虽然与火焰系、假欧氏系、喙齿系、拟蕨系和长喙系等成员构成姐妹关系,但熊猫马先蒿的花冠形态特征明显区别于近缘物种。     

The effect of floral morphology on seed set in <Emphasis Type="Italic">Carthamus tinctorius</Emphasis> Linnaeus (Asteraceae) clones of Sichuan province in China

The relationships among the floral morphologies, breeding system and pollination insects in nine Carthamus tinctorius L. clones were investigated in Ya’an, Sichuan province, China. No significant differences in seed setting rate were observed among the clones following unbagged treatment, but significant differences in seed setting rate were observed among the clones following bagged treatment. Breeding experiments indicated that both reproductive systems (selfing and outcrossing) coexisted in each tested C. tinctorius clone. It exhibited reproductive assurance through automatic self-pollination, which might be an important factor in enhancing the amount of seeds. Among 17 species of visitors, the main effective pollinators were Apis cerana Fabricius, Apis mellifera Linnaeus and Eristalis tenax Linnaeus. All floral morphology traits (corolla length, corolla diameter, pistil length, anther length, stigma length, and stigma–anther separation) showed significant variations among the clones. However, only corolla diameter showed a significant negative correlation with the frequency of pollinator visits and a positive correlation with seed set following unbagged treatment. There was a negative correlation between stigma–anther separation and seed set, and although this was not significant, it could be argued that if a pistil developed that was too long, seed set would decline under natural conditions. Corolla length was significantly positively correlated with stamen and anther length, and corolla diameter was significantly negatively correlated with pistil length. Stigma length was also significantly positively correlated with stamen length. These findings indicate that corolla diameter could significantly affect seed set in C. tinctorius under the conditions in Ya’an, China, and corolla diameter affects seed set by the combined effect of multiple traits.     

A new species of Coreopsis section Pseudoagarista (Asteraceae) from Mexico

Coreopsis queretarensis, a new species from northeastern Mexico belonging to sectionPseudoagarista, is described and illustrated. It is closely related toC. mevaughii of Nueva Galicia but is readily distinguished by leaf shape, involucral bracts, and details of corolla.     

Interaction between oil-collecting bees and seven species of Plantaginaceae

Oil-bee/oil-flower mutualism evolved through multiple gains and losses of the ability to produce floral oil in plants and to collect it in bees. Around 2000 plant species are known to produce floral oils that are collected by roughly 450 bee species, which use them for the construction of nests and for the larval food. The Plantaginaceae contain several Neotropical species that produce floral oils, the main reward offered by these plants. In the genera Angelonia, Basistemon, Monopera and Monttea, mainly associated with Centris bees, the floral oil is produced in trichomes that are located in the inner corolla. The pollinators of a few species in this neotropical clade of Plantaginaceae are known, and the role of flower morphology as well as the requirements from pollinators and the role of other groups of bees in the pollination of these flowers remains unclear. In this paper we provide a list of the flower visitors of seven Plantaginaceae species (six Angelonia species and Basistemon silvaticus) analyzing their behavior to highlight the legitimate pollinators and illustrating little known aspects of flower morphology and oil-collecting apparatuses of the bees. Two general morphological patterns were observed in the Angelonia flowers: deep corolla tube with short lobes, and short corolla tube with long lobes. Corolla tubes of different length result in pollen adherence to different parts of the insect body. The six Angelonia species and B. silvaticus flowers were visited by 25 oil-collecting bee species (10 Centris, 11 Tapinotaspidini and 4 Tetrapedia species), the majority acting as legitimate visitors. The flowers were also visited by illegitimate bee pollinators, which collected pollen but do not transfer it to the female organ. Specialized collectors of Plantaginaceae floral oils present modifications on the first pair of legs, mainly in the basitarsi but also extended to the tarsomeres. The new records of Tapinotaspidini and Centridini species acting as specialized pollinators of Plantaginaceae suggest that there is a geographic variation in the pollinators of the same plant species, and that the evolutionary scenario of the historical relationships between oil-collecting bees and floral oil producing plants is more complex than previously considered.     

Four new species of Adenocalymma (Bignoniaceae) and a key to the species from southeastern Brazil

Four new species of Adenocalymma (Bignoniaceae, Bignonieae) from southeastern Brazil are described and illustrated: A. aurantiacum, characterized by dark orange and infundibuliform corolla; A. cinereum, characterized by shrubby habit, greyish inflorescence, infundibuliform corolla, and exserted stamens; A. gibbosum, characterized by gibbous and orange corolla and an inflorescence with dendritic trichomes; and A. sessile, characterized by sessile leaves and gibbous corolla. A discussion on the relationships of the new taxa and a key to all 29 species of Adenocalymma reported from southeastern Brazil are provided.     

唇形科鼠尾草属新植物

描述了四川（唇形科）鼠尾草属植物一新种,即川西鼠尾草。新植物毛被与花冠管内被长柔毛而独特,接近于粘毛鼠尾草(Salvia roborowskii Maxim.),其区别在于多年生草本,根粗壮,直径1～2 cm;花萼较长,长1～1.2 cm;花冠较长,长约2.1 cm,内面离花冠筒基部约2 mm处,向上长约5 mm一段全被长柔毛（非毛环）,花冠筒近中部向上近直弯曲而逐渐扩大,冠檐上下唇具紫红色斑点。     

Justicia masiaca (Acanthaceae), a new species from northwestern Mexico

Justicia masiaca, a new species endemic to northwestern Mexico, is described, illustrated, and compared with the morphologically similarJ. longii. In its 4-aperturate pollen,Justicia masiaca is unique among those species ofJusticia with elongate, cylindrical corolla tubes that were previously treated inSiphonoglossa.     

Nectarless flowers with deep corolla tubes in Pedicularis: does long pistil length provide an arena for male competition?

Pollinator‐mediated selection does not seem to have a direct influence on the evolution of a long corolla tube in a nectarless flower. We hypothesized that the long pistil length of the nectarless flower with a deep corolla tube provided an opportunity for male competition. Pedicularis siphonantha, a nectarless and partially self‐incompatible lousewort with substantial variation in corolla tube length, was used to test the hypothesis. We tested whether and how corolla tube length affected seed production per capsule and seed germination rate with different pollination treatments. Flowers were hand‐pollinated with pollen from one self donor and one outcross donor and mixed pollen grains consisting of equal amounts from the two donor types, respectively. Additionally, seeds from open‐pollinated flowers with different corolla tube lengths were collected separately for measurement of germination rate. Pollination treatment and corolla tube length significantly affected number of seeds per capsule. Moreover, a significant positive relationship between seeds per capsule and corolla tube length was found when mixed hand pollination was conducted. Seeds of self hand‐pollinated flowers had a lower germination rate than those from outcross‐pollinated flowers. Under open pollination, seeds from flowers with longer corolla tubes tended to have higher germination rate. In P. siphonantha, outcross pollen may have a higher probability of contributing to the next generation when transferred to flowers with longer corolla tubes. The pistil length, therefore, should be seen as a female choice mechanism, which provides an arena for male‐to‐male competition. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 526–532.     

Hemiboea lutea sp. nov. (Gesneriaceae) from Guangxi,China

Hemiboea lutea F. Wen, G. Y. Liang & Y. G. Wei, a new species in Gesneriaceae is described and illustrated from Guangxi, China. It differs from the similar species H. cavaleriei by having sessile or subsessile leaves, longer peduncles (6–10 cm), spheroidal or triangular‐spheroidal subinvolucre, 5‐divided calyx with lobes fused for 1/3 of their length, revolute and uncinate apex of calyx lobes, larger bright yellow corolla (5–7 cm long), longer staminodes with indistinctively uncinate anther and longer pistil (3.5–3.7 cm).     

Oreocharis xieyongii,an unusual new species of Gesneriaceae from western Hunan,ChinaOA

A new species,Oreocharis xieyongii T.Deng,D.G.Zhang & H.Sun,from Hunan Province,central China,is described.The combination of purple zygomorphic corolla with longer adaxial lobes and exserted stamens defines the species and discriminates it from all other current Oreocharis species.Morphological traits of the new species were compared to those of two similar species,Oreocharis xiangguiensis and 0.rubrostriata.Phylogenetic analysis indicates that the new species is nested within the Oreochari...     

Salvia petrophila sp. nov. (Lamiaceae) from north Guangxi and south Guizhou,China

Salvia petrophila G. X. Hu, E. D. Liu & Yan Liu, a new species from the Chinese provinces of north Guangxi and south Guizhou, is described and illustrated. The new species is similar to S. miltiorrhiza, but can easily be distinguished by its shorter, unbranched stem, subsucculent simple leaf, longer pedicel and corolla tube, oblong‐entire middle lobe of lower corolla lip and larger oblate pollen. It is included in S. sect. Drymosphace on the basis of its falcate‐compressed upper corolla lip and connivent posterior connectives. Trichome and pollen micromorphology of the new species and similar species are described and compared. Additionally, assessment of the conservation status, current geographical distribution and notes on ecology of the new species are given.     

Corolla tube formation in the primulaceae and ericales

Corolla tube formation was investigated anatomically for 13 species of the Primulaceae and Ericales. In the Primulaceae, petal primordia appear after the stamen initiation. The lower portion of the corolla tube, the portion under the stamen insertion, is derived from the ring-like structure formed immediately after the stamen initiation. Petal bases extend laterally, and connect mutually on the ring-like structure. The upward growth at the connected regions results in the formation of a corolla tube, which develops into the upper portion of the corolla tube. In the Ericales, except forClethra, the corolla tube is formed by the mutual connection of petal bases. This tube elongates inRhododendron, Leucothoe andPieris. However, inPyrola, Ledum andTripetaleia, the elongation of this tube is meager, resulting in a dialypetalous condition in the mature state. Three petals ofTripetaleia may be derived from the partial connection of five petal primordia in a very early stage of the corolla development. From the data obtained in the studies on the corolla tube formation, three modes of the corolla tube formation are suggested; postgenital fusion, connection of petal bases, elongation of the ring-like common base.