Exploitation of floral resources on Sparattosperma leucanthum (Bignoniaceae): foraging activity of the pollinators and the nectar and pollen thieves

The interaction between floral visitors and plants in natural ecosystems has become a major subject in studies on biodiversity conservation. However, there is a very complex interaction between the community of floral visitors and the plant species foraged by them in the natural environment and little is known about the foraging activity of these visitors. Thus, the objective of this study was to determine the composition of the community of floral visitors to Sparattosperma leucanthum in an area under natural regeneration, focusing on the assessment of the exploitation of floral resources by the predominant visitors and effective pollinators. To accomplish this objective, we recorded the activity and behavior of the floral visitors throughout the day in a 2- to 3-m² area of flowering branches of S. leucanthum. The model established in the current study comprises the occurrence of a high number of species with few individuals, whereas few species are represented by many individuals. The five predominant species were Apis mellifera, Trigona spinipes, Bombus sp1, Hylocharis chrysura, and Halictidae type 1. Of these species, only Bombus sp1 seemed to effectively pollinate the flowers.     

Differentiation of floral color and odor in two fly pollinated species ofMetrodorea (Rutaceae) from Brazil

We investigated if differences in morphological characters in two species ofMetrodorea (Rutaceae) from Brazilian semideciduous forests correspond to some pollination divergence.M. nigra andM. stipularis are sympatric species, display a similar floral morphology, are protandrous, self-incompatible, their flower periods overlap, and both are pollinated by flies.M. nigra main pollinators arePseudoptiloleps nigripoda (Muscidae) andFannia sp. (Fanniidae);M. stipularis major pollinators arePhaenicia eximia (Calliphoridae),Palpada sp. andOrnidia obesa (Syrphidae). The distinct floral odor (disagreeable inM. nigra and sweet inM. stipularis) and color (brownish violet vs. pale yellow) determine the differences on type and number of floral visitors observed. Several species from semideciduous forests initially considered to be pollinated by diverse insects, present flies as main pollinators, stressing the importance of fly pollination in such habitats.     

Reproductive biology and pollination of Utricularia reniformis A.St.‐Hil. (Lentibulariaceae)

Utricularia reniformis is an endemic Brazilian carnivorous plant, most common in high‐altitude grasslands. Knowledge of the reproductive biology of U. reniformis is essential for planning conservation strategies, but it is currently poorly understood. Thus, we studied the floral morphology, floral biology, breeding system and pollination of this species. U. reniformis produces and stores nectar in the flower spur, a classic feature of bee‐pollinated flowers, and we recorded Xylocopa sp. and Bombus sp. as pollinators. Moreover, although it is self‐compatible it is an obligate animal‐pollinated species, as the sensitive stigma avoids self‐pollination. However, in natural conditions reproductive success is low due to the rarity of visits from pollinators. We suggest that the low reproductive success caused by a deficit of pollinators may affect gene flow, causing loss of genetic diversity in U. reniformis.     

Wasatchian (Early Eocene) pollen floras from the Red Hot Truck Stop, Mississippi, USA

Sediments at the Red Hot Truck Stop (RHTS), Mississippi, USA are important because they contain the lowest latitude record of both the earliest known Eocene plant and mammal fossils in North America. The RHTS contains the uppermost Tuscahoma Formation and the lowermost part of the basal Bashi and Hatchetigbee formations. The Tuscahoma Formation is composed of glauconitic sands and silts that represent estuarine to shallow marine sediments. Faunal remains indicate that the RHTS section belongs to the Wasatchian North American land mammal age and specifically to the lower Graybullian subdivision. Pollen and spore floras from the RHTS are moderately diverse (113 taxa) and contain families that today are associated with warm‐adapted vegetation types such as Annonaceae, Bombacaceae, Burseraceae and palms. Eocene first occurrences are represented by Brosipollis sp., Celtispollenites sp., Interpollis microsupplingensis, cf. Nuxpollenites psilatus, Platycarya spp., Retistephanocolporites sp. and Symplocos? contracta and by one genus of pteridophyte spore (Granulatisporites sp.). The overall composition and within‐sample diversity of the sporomorph flora is more similar to the Hatchetigbee Formation (early Eocene) than to the middle Tuscahoma Formation (late Palaeocene) but among‐sample diversity remains unchanged across the Palaeocene/Eocene boundary. The distinct composition of the RHTS demonstrates that floral change across the Palaeocene/Eocene boundary is complex and composed of several phases of floral change.     

Floral biology and reproductive ecology ofClusia nemorosa (Clusiaceae) in northeastern Brazil

Between March 1993 and May 1995 the floral biology and the phenology ofClusia nemorosa G. Mey. (Clusiaceae) were studied in two dioecious populations in Pernambuco State, and some observations were made in gynodioecious populations, that were encountered only in Bahia State. The species flowers from June to January/February. The flowers are bowl shaped, and last only one day. The floral reward is resin which is produced by staminodia in all types of flowers. The sex ratio was 1:1 for the studied populations. The pollen viability was approximately 98%. Apomixis was not observed. The rate of fruit set, in hermaphrodite individuals, under natural conditions and the sex ratio of the gynodioecious populations studied suggest that the hermaphrodite individuals may behave as males.Clusia nemorosa is melittophilous and was visited by 16 species of bees. The main pollinators wereEuplusia mussitans, E. iopyhrra, Eulaema cingulata, E. nigrita, Euglossa cordata andEuglossa sp.     

Spinicaudatans and ostracods (Crustacea) from the Montceau Lagerstätte (Late Carboniferous, France): morphology and palaeoenvironmental significance

Spinicaudatans and ostracods form two components of the diverse arthropod fauna from the Montceau Lagerstätte (Stephanian, France). Spinicaudatans are represented by Montcestheria orri gen. and sp. nov. and Euestheria feysi sp. nov., and ostracods by a single species, Carbonita sp. aff. salteriana (Jones, 1862). Allied forms such as Montcestheria sp. aff. orri, Montcestheria sp. and Euestheria cebennensis (Grand'Eury, 1890), all from coeval localities in France, are also described. Montcestheria gen. nov. has carapace features, external (possibly sexual) dimorphism, preserved soft parts (e.g. appendages, gut) and resting eggs similar to those of Recent spinicaudatans, suggesting comparable lifestyles, reproductive strategies and feeding modes. Detailed anatomical comparisons are made with Cyzicus tetracerus from Recent ephemeral freshwater ponds. The ostracods belong to the Superfamily Carbonitoidea, which is a recurrent component of Carboniferous non‐marine biotas. Spinicaudatan‐rich assemblages typically occur in several Westphalian–Stephanian Lagerstätten (including Montceau) and localities from Europe and North America, where freshwater conditions prevailed, indicating that the group had already colonized continental waters by the Late Carboniferous. Similarities with the fauna from Recent temporary freshwater ponds (e.g. low diversity/high density spinicaudatan‐ostracod populations, synchronous spinicaudatan populations developing from resting eggs, high diversity/low density insects, amphibians) suggest the presence of temporary or ephemeral aquatic environments at Montceau as part of a complex limnic ecosystem. Flooding may have been the main driving force by which faunal and floral elements drifted away from their respective biotopes into the depositional areas, thus explaining the co‐occurrence of terrestrial (e.g. myriapods, scorpions, plants), amphibian and aquatic (e.g. conchostracans and syncarids from temporary and permanent settings, respectively) elements in fossil assemblages.     

Primary nectar robbing by Apis mellifera (Apidae) on Pyrostegia venusta (Bignoniaceae): behavior,pillaging rate,and its consequences

The interactions between plants and their pollinators are the result of convergent evolution of floral attributes reflecting pressure exerted by pollinators. Nonetheless, the strategies employed by floral visitors to collect floral resources are extremely complex, and commonly involve theft or robbery in addition to pollination. We describe here the behavioral repertory of Apis mellifera during the collection of the floral resources, and evaluated the robbing rates of A. mellifera on the buds and flowers of Pyrostegia venusta during periods of intense and sparse flowering. We recorded the behaviors exhibited by foraging bees while collecting floral resources, quantified the numbers of floral buds and flowers with perforations in their corolla tissues, and determined whether that damage reduced nectar production. The evaluations were conducted during two distinct periods: during the period of intense flowering of P. venusta, and during the period of sparse flowering. Nectar robbing was observed during 93.4% of the visits of foraging A. mellifera bees, while nectar theft was observed during only 0.7% of the visits, and pollen theft during 5.9%. The robbing of floral buds and flowers was most intense during the period of heavy flowering. Flowers that had been intensely robbed secreted significantly less nectar than those non-robbed. The unusual nectar robbing activities of A. mellifera, especially during the period of intense flowering indicates an optimization of access to larger volumes of food resources. Our results therefore point to a major limitation of nectar per floral unit during the intense flowering period of P. venusta due to the high activity of nectar robbing by A. mellifera bees.

     

Flowering mechanisms,pollination strategies and floral scent analyses of syntopically co‐flowering Homalomena spp. (Araceae) on Borneo

In this study, the flowering mechanisms and pollination strategies of seven species of the highly diverse genus Homalomena (Araceae) were investigated in native populations of West Sarawak, Borneo. The floral scent compositions were also recorded for six of these species. The selected taxa belong to three out of four complexes of the section Cyrtocladon (Hanneae, Giamensis and Borneensis). The species belonging to the Hanneae complex exhibited longer anthesis (53–62 h) than those of the Giamensis and Borneensis complexes (ca. 30 h). Species belonging to the Hanneae complex underwent two floral scent emission events in consecutive days, during the pistillate and staminate phases of anthesis. In species belonging to the Giamensis and Borneensis complexes, floral scent emission was only evident to the human nose during the pistillate phase. A total of 33 volatile organic compounds (VOCs) were detected in floral scent analyses of species belonging to the Hanneae complex, whereas 26 VOCs were found in samples of those belonging to the Giamensis complex. The floral scent blends contained uncommon compounds in high concentration, which could ensure pollinator discrimination. Our observations indicate that scarab beetles (Parastasia gestroi and P. nigripennis; Scarabaeidae, Rutelinae) are the pollinators of the investigated species of Homalomena, with Chaloenus schawalleri (Chrysomelidae, Galeuricinae) acting as a secondary pollinator. The pollinators utilise the inflorescence for food, mating opportunities and safe mating arena as rewards. Flower‐breeding flies (Colocasiomyia nigricauda and C. aff. heterodonta; Diptera, Drosophilidae) and terrestrial hydrophilid beetles (Cycreon sp.; Coleoptera, Hydrophilidae) were also frequently recovered from inflorescences belonging to all studied species (except H. velutipedunculata), but they probably do not act as efficient pollinators. Future studies should investigate the post‐mating isolating barriers among syntopically co‐flowering Homalomena sharing the same visiting insects.     

Floral development in Nymphaea tetragona (Nymphaeaceae)

We describe in detail the floral ontogeny of Nymphaea tetragona from a wild population to provide evidence regarding the phylogenetic position of Nymphaea and to reveal evolutionary trends of flowers in Nymphaeaceae by comparison with that of the other genera. Four sepals are initiated unidirectionally. The basal petals are initiated unidirectionally and alternate with the sepals. The dome‐shaped floral apex continues to expand and produces more petal and stamen primordia. The remaining petals and all stamens are initiated in spirals or whorls. Later, the periphery of the floral apex grows more quickly than the centre and results in a depression in the centre of the apex after all stamens have been initiated. Carpels are simultaneously initiated in a cycle at the periphery of the depression. They are ascidiate. After all organs have been initiated, the centre of the depression on the floral apex grows and develops into a globular structure. The connected inferior ovary, stigma caps and the globular floral apex together form an extragynoecial compitum. Within Nymphaeaceae, the floral ontogeny of Nymphaea is most similar to that of Euryale and Victoria. It differs more from Ondinea and Barclaya, and differs most from Nuphar. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 211–221.     

Floral volatile sesquiterpenes of Elsholtzia rugulosa (Lamiaceae) selectively attract Asian honey bees

There are few floral volatiles of compounds that have been properly assessed for attracting pollinators. The intense plant odour of Elsholtzia rugulosa (Lamiaceae) to humans may be attributed to the presence of high concentrations of β‐caryophyllene. In a previous study, Zhang, Yang, and Zhang (Scientific Reports, 6, 2016a, 276161) speculated that the presence of β‐caryophyllene attracts pollinators (e.g., honey bees) to its flowers, an assumption that was assessed through the exploration of the functional significance of specific floral volatile compounds and the evaluation of their effects on the behaviour of Apis cerana (Asian honey bees; a known pollinator) and two non‐pollinators, a hornet (Vespa velutina) and a bumblebee (Bombus sp.). The results from these behavioural experiments indicated that both β‐caryophyllene and β‐elemene (both naturally found in flowers of E. rugulosa) were individually attractive to the Asian honey bees. Moreover, the combination of the two was more effective than either of them separately. In contrast, neither compound, nor a blend of the two at different concentrations, was attractive to the hornet and bumblebee species. These results demonstrate that β‐caryophyllene and β‐elemene play a key signalling role in attracting Asian honey bees to E. rugulosa.     

Salvia lagochila sp. nov. (Lamiaceae) from Yunnan,China

A new species, Salvia lagochila T. Wang & L. Wang sp. nov. (Lamiaceae) is described from Shangri‐La County in northwestern Yunnan, China. The diagnostic morphological characteristics in relation to closely similar species are discussed. Nutlet micro‐morphology was examined using scanning electron microscopy, and leaf anatomic structures were studied using light microscope. The new species is included in S. subgen. Salvia sect. Eurysphace subsect. Perennes on the basis of its perennial habit, entire upper floral lip and arcuate anther connectives.     

Floral ecology of Oreocharis pumila (Gesneriaceae): a novel case of sigmoid corolla

Attraction of pollinators and successful pollen transfer represent the primary targets of selection during flower evolution, leading to repeated evolutionary shifts between pollinators and consequently to the diversification of floral forms. However, most studies in floral evolution focus on the characteristics of flowers with straight corolla tube. Here, we report on an unusual form of sigmoid corolla combined with protandry and herkogamy in a Chinese species of Gesneriaceae, Oreocharis pumila (formerly Opithandra pumila). Contrary to species with sigmoid corollas studied previously, the base of the corolla tube of this species is inclined at an oblique angle downwards before the tube bends forward, and the stigma and anthers are included in the upper part of the corolla tube. The plants were found to be self‐compatible but incapable of autonomous selfing. Successful pollination was found to depend fully on the presence of insect pollinators (Nomia sp.) and pollen grains are the greatest reward for the visitors. Different from the other sigmoid flowers, the sigmoid corolla of O. pumila was not found to favor insect pollinators with long flexible proboscises. A mechanical fit between floral morphology and pollinator was found, in which only small insect visitors with specialized visiting behavior are legitimate pollinators. The protandry combined with herkogamy in the sigmoid corolla tube strongly ensures pollination efficiencies. Oreocharis pumila is the only species with sigmoid corolla in the genus Oreocharis. We hypothesize that such a corolla has arisen through selection due to inadequate pollination in early spring in the mountainous habitat that O. pumila occupies.     

Selection of plant parts by Depressaria multifidae (Lep., Oecophoridae) on its seasonally-restricted hostplant, Lomatium grayi (Umbelliferae)

ABSTRACT.

• 1 Depressaria multifidae Clarke feeds on a broader variety of Umbelliferae plant parts than other Depressaria species.
• 2 Early instar larvae feed in the sheaths surrounding floral buds and leaves. Later instar larvae feed in the sheaths and floral stems and on flowers and leaves.
• 3 Floral stems bored by larvae had significantly larger basal stem diameters than floral stems that were not bored. Smaller stems usually have umbels with only male flowers, and wither after flowering, too soon for larvae to complete development. In contrast, larger stems often have umbels with some hermaphroditic flowers, which remain green and erect long enough for larvae to complete development. Hence, selection may favour larvae that bore only in relatively large stems.
• 4 In the laboratory, larvae fed sheaths with enclosed floral buds, flowers, or leaves all pupated at the same weight, but larvae fed floral stems pupated at a significantly lower weight. Larval and pupal development time was the same on all plant parts.
• 5 In the field, larvae restricted to a single umbel throughout development pupated at the same weight as those restricted to a single leaf.
• 6 Unlike in other Depressaria species, nitrogen levels only partly correspond to the pattern of use of plant parts in D.multifidae. Nitrogen values varied as follows: floral buds > immature leaves ≥ flowers > floral stalks > sheaths excluding floral buds or leaves.
• 7 The broad variety of plant parts used by D.multifidae may result partly from the problem of feeding on a small, seasonally restricted hostplant; the greater use of sheaths and floral stems than in other Depressaria species may result from selection for safety from parasites or predators.
• 8 The results for D.multifidae indicate that the way in which an insect feeds on a plant species can vary broadly even at a single site.

     

Reproductive biology of the melon cactus, Melocactus curvispinus (Cactaceae)

We examined the reproductive biology of Melocactus curvispinus Pfeiffer (Cereeae, Cactoideae) in xeric areas of northern Venezuela. Floral traits correspond to a classic hummingbird-pollination syndrome; however, pollination is shared between hummingbirds, Leucippus fallax (Bourcier 1843), and anthophorid bees, Ceratina sp. Reproduction occurs during most of the year. Anthesis and nectar secretion occur between noon and sunset. Average daily nectar production per flower was 163.1 l, nectar sugar concentration between 29.1 and 30.2% (w/w). Hummingbirds promoted inter-plant pollen movement and were relatively more reliable floral visitors than anthophorid bees, but these insects had a higher frequency of floral visits (28.75/day) than hummingbirds (4.96/day). M. curvispinus is self-compatible and autogamous. By combining extended reproductive activity, frequent animal-mediated pollination, and selfing capabilities, this cactus possesses a mating strategy that guarantees reproduction under variable environmental conditions. We argue that based on its reproductive biology, M. curvispinus should be considered an example of evolutionary transition towards selfing within tribe Cereeae.     

Juvenility and flowering of Brunonia australis (Goodeniaceae) and Calandrinia sp. (Portulacaceae) in relation to vernalization and daylength

Background and Aims

The time at which plants are transferred to floral inductive conditions affects the onset of flowering and plant morphology, due to juvenility. Plants of Brunonia australis and Calandrinia sp. were used to investigate whether Australian native ephemeral species show a distinct juvenile phase that can be extended to increase vegetative growth and flowering.

Methods

The juvenile phase was quantified by transferring seedlings from less inductive (short day and 30/20°C) to inductive (vernalization or long day) conditions at six different plant ages ranging from 4 to 35 d after seed germination. An increase in days to first visible floral bud and leaf number were used to signify the end of juvenility.

Key Results

Brunonia australis was receptive to floral inductive long day conditions about 18–22 d after seed germination, whereas plants aged 4–35 d appeared vernalization sensitive. Overall, transferring plants of B. australis from short to long day conditions reduced the time to anthesis compared with vernalization or constant short day conditions. Calandrinia sp. showed a facultative requirement for vernalization and an insensitive phase was not detected. Floral bud and branch production increased favourably as plant age at time of transfer to inductive conditions increased. Younger plants showed the shortest crop production time.

Conclusions

Both species can perceive the vernalization floral stimulus from a very young age, whereas the photoperiodic stimulus is perceived by B. australis after a period of vegetative growth. However, extending the juvenile phase can promote foliage development and enhance flower production of both species.     

Arabidopsis thaliana CENTRORADIALIS homologue (ATC) acts systemically to inhibit floral initiation in Arabidopsis

Floral initiation is orchestrated by systemic floral activators and inhibitors. This remote‐control system may integrate environmental cues to modulate floral initiation. Recently, FLOWERING LOCUS T (FT) was found to be a florigen. However, the identity of systemic floral inhibitor or anti‐florigen remains to be elucidated. Here we show that Arabidopsis thaliana CENTRORADIALIS homologue (ATC), an Arabidopsis FT homologue, may act in a non‐cell autonomous manner to inhibit floral initiation. Analysis of the ATC null mutant revealed that ATC is a short‐day‐induced floral inhibitor. Cell type‐specific expression showed that companion cells and apex that express ATC are sufficient to inhibit floral initiation. Histochemical analysis showed that the promoter activity of ATC was mainly found in vasculature but under the detection limit in apex, a finding that suggests that ATC may move from the vasculature to the apex to influence flowering. Consistent with this notion, Arabidopsis seedling grafting experiments demonstrated that ATC moved over a long distance and that floral inhibition by ATC is graft transmissible. ATC probably antagonizes FT activity, because both ATC and FT interact with FD and affect the same downstream meristem identity genes APETALA1, in an opposite manner. Thus, photoperiodic variations may trigger functionally opposite FT homologues to systemically influence floral initiation.     

Floral and pollinator behaviour of flexistylous Bornean ginger, Alpinia nieuwenhuizii (Zingiberaceae)

Flexistyly is a unique floral mechanism involving extreme curving of the style. It was first described in Chinese ginger (Amomum, Zingiberaceae). This is a pioneer report on flexistylous gingers of Malesia, where most species of this family grow. We observed the floral behaviour and flower visitors in Alpinia nieuwenhuizii Val., a Bornean endemic. Although the floral behaviour and effective pollinators (carpenter bees, Xylocopa) were similar between the Bornean species and the previously reported flexistylous Alpinia, the pollinator behaviour between them strikingly differed with regard to the visit frequency of the pollinators showing a bimodal pattern during the day. This was a better match for the floral behaviour of the flexistylous Alpinia. Some gender differentiation observed between the two types of morphs is also discussed in the present study.     

圆唇苣苔属(Gyrocheilos)花柱侧偏弯折现象及其传粉适应机制

圆唇苣苔属(Gyrocheilos)是苦苣苔科的中国特有属,有5种,全部狭域分布在我国西南及广东的高海拔山区。圆唇苣苔属所有物种的花柱侧偏且花柱顶端呈90°弯折,使得柱头位于花开口的中央位置。这种独特的侧偏弯折花柱结构,说明圆唇苣苔属可能有着特殊的演化历史和适应机制。为揭示这种特殊的花柱侧偏弯折现象的发生范围、发育过程及其传粉适应机制,该研究在圆唇苣苔(Gyrocheilos chorisepalus)、折毛圆唇苣苔(G. retrotrichus)和微毛圆唇苣苔(G. microtrichus)3个物种中开展了花部综合征观察,并研究了广东大雾岭保护区内的折毛圆唇苣苔花发育过程、花部特征和繁育系统以及传粉过程。结果表明:(1)微毛圆唇苣苔只有花柱左偏弯折现象,而圆唇苣苔和折毛圆唇苣苔虽然大部分花是花柱左偏弯折,但在部分个体中出现了少量的花柱右偏弯折现象(占种群总花数的2%～3%)。(2)传粉观察发现,折毛圆唇苣苔在花蕾期即出现了花柱弯折现象,2个可育雄蕊的花药合生、位于花冠筒喉部中央位置,与侧偏花柱不存在左右镜像对称关系。(3)折毛圆唇苣苔的花粉胚珠比(P/O)为456.98±15.55,属于兼性异交繁育系统。折毛圆唇苣苔存在一定的传粉限制,自交授粉可以结实,但异交种子萌发率更高,可能存在近交衰退。(4)折毛圆唇苣苔的访花昆虫较少,访花频率较低,主要访花昆虫有隧蜂、熊蜂、食蚜蝇等; 熊蜂体型较大,访花时降落在弯折花柱和花瓣下唇,胸部侧面及下部能有效接触到柱头。(5)反射率结果显示,折毛圆唇苣苔花瓣反射波长范围集中在紫光和蓝紫光区域,花冠的反射波长范围与蜂类视觉范围一致且花冠筒外侧和花瓣下唇的反射强度最大,更容易吸引蜂类落置在花冠宽大的下唇; 圆唇苣苔属的花柱侧偏弯折现象可能来自近缘的长蒴苣苔属(Didymocarpus)的花柱下弯现象或镜像花(mirror-image flowers)。综上认为,这种侧偏弯折的花柱,可能通过提供昆虫降落平台,使得柱头位于花开口中央和花瓣下唇的上方位置,提高了柱头接触访花昆虫的概率,是适应高海拔地区低频率访花者的一种机制。     

An APETALA3 homolog controls both petal identity and floral meristem patterning in Nigella damascena L. (Ranunculaceae)

Flower architecture mutants provide a unique opportunity to address the genetic origin of flower diversity. Here we study a naturally occurring floral dimorphism in Nigella damascena (Ranunculaceae), involving replacement of the petals by numerous sepal‐like and chimeric sepal/stamen organs. We performed a comparative study of floral morphology and floral development, and characterized the expression of APETALA3 and PISTILLATA homologs in both morphs. Segregation analyses and gene silencing were used to determine the involvement of an APETALA3 paralog (NdAP3–3) in the floral dimorphism. We demonstrate that the complex floral dimorphism is controlled by a single locus, which perfectly co‐segregates with the NdAP3–3 gene. This gene is not expressed in the apetalous morph and exhibits a particular expression dynamic during early floral development in the petalous morph. NdAP3–3 silencing in petalous plants perfectly phenocopies the apetalous morph. Our results show that NdAP3–3 is fully responsible for the complex N. damascena floral dimorphism, suggesting that it plays a role not only in petal identity but also in meristem patterning, possibly through regulation of perianth organ number and the perianth/stamen boundary.