Larger Flowers Research Articles

Sphyrospermum grandiflorum (Ericaceae: Vaccinieae): a new epiphytic shrub from south eastern Ecuador

A new morphologically distinct species of Ericaceae (Vaccinieae) is here described and illustrated. Sphyrospermum grandiflorum, is an epiphytic shrub endemic to the environs of Cordillera del Cóndor, in southeastern Ecuador. It is characterized by its large yellow flowers.

A phylogenetic and biogeographic study of Rafflesia (Rafflesiaceae) in the Philippines: Limited dispersal and high island endemism

Rafflesia (Rafflesiaceae) is a small endo-holoparasitic Asian plant genus known for its exceptionally large flowers, rare species, and high island endemism. In this study, phylogenetic (parsimony and Bayesian inference) and biogeographic (BioGeoBEARS) analyses of DNA sequence data (atp6 and matR genes, and nad1 B-C intron from the mitochondrial genome, and the nuclear ribosomal internal transcribed spacer) were used to reconstruct the phylogenetic relationships among 12 of the 13 known Philippine Rafflesia species and to determine the timing and pathways of their diversification. The results of these analyses confirm those of previous Rafflesia studies (which were largely focused on non-Philippine species) in finding pronounced biogeographic patterns. They suggest that dispersal between islands has been relatively uncommon, and indicate that the high island endemism of Rafflesia is a result of poor inter-island dispersal abilities. The results further suggest that its ancestral range might have been in Borneo, and that its lineages and species evolved earlier and more gradually than previously assumed.

Studies on Colchicine Induced Chromosome Doubling for Enhancement of Quality Traits in Ornamental Plants.

Polyploidy has the utmost importance in horticulture for the development of new ornamental varieties with desirable morphological traits referring to plant size and vigor, leaf thickness, larger flowers with thicker petals, intense color of leaves and flowers, long lasting flowers, compactness, dwarfness and restored fertility. Polyploidy may occur naturally due to the formation of unreduced gametes or can be artificially induced by doubling the number of chromosomes in somatic cells. Usually, natural polyploid plants are unavailable, so polyploidy is induced synthetically with the help of mitotic inhibitors. Colchicine is a widely used mitotic inhibitor for the induction of polyploidy in plants during their cell division by inhibiting the chromosome segregation. Different plant organs like seeds, apical meristems, flower buds, and roots can be used to induce polyploidy through many application methods such as dipping/soaking, dropping or cotton wool. Flow cytometry and chromosome counting, with an observation of morphological and physiological traits are routine procedures for the determination of ploidy level in plants.

Paphiopedilum erythroanthum, a new species of slipper orchid (Cypripedioideae, Orchidaceae) from China based on morphological and molecular data

A new species of Paphiopedilum (Orchidaceae) from Yunnan, China is described and illustrated based on examining morphological and molecular evidence. Morphological comparisons indicate that the new species P. erythroanthum is somewhat similar to P. henryanum, from which it differs by its shorter scape, larger and purple-red flower without purple spots, an obovate dorsal sepal, narrowly oblong petals with recurved apex and a cordate staminode. Molecular analyses of combined nuclear and plastid datasets (ITS and matK) indicate that P. erythroanthum is sister to P. notatisepalum, which has leaves with large yellow spots, a shorter scape, larger flower, white sepals and petals with large purple spots. The morphological and molecular evidence support the hypothesis that P. erythroanthum is a new species.

An outstanding new species of Senna (Fabaceae: Caesalpinioideae) from southern Puebla, Mexico

Senna acatlanensis is described and illustrated here. This species is restricted to a forest ecotone in southern Puebla (Mexico), and stands out by its unique large asymmetric flowers, with yellow petals that do not fade away to reddish-brown as they dry-out, heteromorphic and variable androecium; with four staminodes, ten or less fertile stamens; by its pendulous, cylindrical fruits, with chartaceous strigillose valves, and inter-seminal septa with a black-pulpy endocarp that surrounds exareolate seeds. These morphological attributes in addition to leaves with two pairs of leaflets, anthers with beaks, gynoecium multi-ovulated, and transversely oriented seed, turned broadside to the septa placed this new species within the series Bacillares. Illustrations, taxonomic comments, distribution and conservation status are provided with a key to the Mexican species of series Bacillares.

A new rheophytic species of Syzygium Gaertn. (Myrtaceae) from Assam, North East India

A new species of Syzygium Gaertn. (Myrtaceae) is described from North East India: Syzygium nivae Barbhuiya, J.Sarma & S.Dey, sp. nov. The new species is a rheophyte, which is restricted to the Kopili riverbed of West Karbi Anglong district of Assam. The present species shows little affinity with Syzygium khasianum (Duthie) N.P.Balakr. in having lanceolate leaves, paniculate inflorescence and calyptrate petals, but differs in various aspects, such as shrubby rheophytic plant habit, narrower leaves, non-caudate leaf apex, shorter peduncles, larger flowers etc.

Hardy Hibiscus for Florida Landscapes

Hardy hibiscus are an overlooked group of perennials with tremendous potential for the landscape. Hardy hibiscus are herbaceous perennial members of the genus, Hibiscus. They are large-flowered, fast-growing plants up to 15 feet tall and 4 to 8 feet wide. They are close relatives of the tropical hibiscus (Hibiscus rosa-sinensis) seen commonly in the landscapes of southern and central Florida. Unlike their tropical counterparts, however, hardy hibiscus are much more cold hardy, vigorous, and long lasting, and they have larger flowers. This document is ENH999, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date October 2005. 
 ENH999/EP245: Hardy Hibiscus for Florida Landscapes (ufl.edu)

Hippeastrum peruvianum (Amaryllidaceae), a New Species from Northern Peru, and Notes on a Naturalized Species of Crinum First Described as Hippeastrum

A new species of Hippeastrum Herb. (Amaryllidaceae) from the department of Amazonas, Peru, is described and illustrated here. Hippeastrum peruvianum Meerow & Campos-Rocha features floral morphology unique among the other species of the genus occurring in the country. It has similarities with H. miniatum (Ruiz & Pav.) Herb. and H. reginae (L.) Herb. but is distinguished readily by its larger flowers, distinct coloration pattern, and trifid stigma. The new species is known only from the type collection by Paul C. Hutchison in 1958. It was determined as H. miniatum in error and has apparently been widely cultivated, especially in California, either under that name or erroneously considered a hybrid. We additionally observe that H. ugentii Ochoa, described from Peru and later transferred to Crinum L., is the naturalized South African species C. moorei Hook. f.

A benefit to providing information? Flower size cues, plant attractiveness, and plant visit length

Abstract In many plant species, flower size is correlated with the production of floral rewards such as nectar and pollen and, therefore, provides information to pollinators about flower quality. However, how relationships between flower size and rewards influence plant fitness is not well understood. In particular, it is unclear whether indicating to pollinators which flowers are unrewarding harms or benefits plants. We used a laboratory system with artificial flowers to examine bumblebees’ (Bombus impatiens) responses to plants that had flower size as an informative cue (with large flowers rewarding and small flowers unrewarding) as compared with “deceptive” plants that had a mixture of rewarding and unrewarding large flowers and plants with only large, rewarding flowers. Bees had previously foraged in a context in which only large flowers provided rewards. Small flowers were visited less often than large flowers. In comparing plants with different numbers of flowers, we found that small flowers, although they added less to a plant’s attractiveness than large flowers, did increase a plant’s attractiveness if present in sufficient number. Furthermore, plants with informative cues received substantially fewer flower visits per plant visit in comparison with deceptive plants, even when the plants with informative cues had a larger number of flowers. Cues identifying unrewarding flowers could, therefore, reduce rates of within-plant pollen movement, increasing the plant’s fitness gains per flower visit. Their contribution to whole-plant attractiveness and avoidance of inbreeding could help explain why many plants produce small, relatively unrewarding flowers even though pollinators avoid visiting them.

Use of genetic resources to develop new commercial Rhododendron simsii hybrids

Rhododendron simsii Planch. hybrid or pot azalea is the most important ornamental plant in Belgium. At least four different species (R. simsii, Rhododendron indicum, Rhododendron scabrum and Rhododendron mucronatum) have contributed to modern hybrids. These species are found in parts of China and Japan. R. simsii introduced the early flowering trait and the ability to produce flower sports. The other species contributed to the diversification of flower color (purple, carmine red), large flowers and specific plant habitus. The Instituut voor Landbouw-, Visserij- en Voedingsonderzoek (ILVO) holds a large gene bank of pot azalea accessions and their wild relatives. To safeguard this gene bank, the core collection is also partly kept in cryopreservation. Gene bank accessions are used for both genetic studies and breeding. In recent years, we have specifically focused on introgression of traits such as new flower and growth forms, fragrance, and disease resistance. The introduction of such specific traits from a wild species into elite breeding material is time consuming, as several backcrosses are necessary. For some characteristics, i.e., disease resistance, adapted screening methods have been developed that enable us to select more adequately.

Reduced reproductive success of the endangered tree brazilwood (Paubrasilia echinata, Leguminosae) in urban ecosystem compared to Atlantic forest remnant: lessons for tropical urban ecology

Human activities have drastically altered natural ecosystems, mostly by converting forests into agricultural and urban areas. Brazilwood (Paubrasilia echinata) is an endangered tree endemic to the Brazilian Atlantic forest originally occurring along the whole coast. The species is largely planted in urban areas due to its ornamental potential. In this paper, we compared the phenology, floral traits and the reproductive success of P. echinata between urban and natural ecosystems. We have hypothesized that individuals in urban ecosystem will have: i) reproductive phenophases lasting longer than in natural, ii) lower number of pollen grains and ovules per flower, iii) lower richness and frequency of flower visitors, and iv) lower natural fruit and seed set. The study was carried out in urban green spaces of the city of Recife and in an Atlantic forest remnant, both in Pernambuco State, northeastern Brazil. The species flowered and fruited practically all year round in the urban ecosystem, contrasting with the annual pattern of flowering and fruiting observed in the natural area. We documented that brazilwood trees in urban areas had smaller inflorescences, fewer flowers/inflorescences, larger flowers, less pollen/flower, lower richness of floral visitors and lower fruit and seed set when compared to natural ecosystem. Also, when considering the most frequent effective pollinator, the invasive bee Apis mellifera predominated in urban, whereas the autochthonous pollinator Centris aenea prevailed in natural. Moreover, C. aenea acted as occasional pollinator in urban area because the flowers of P. echinata are larger in this ecosystem. Independent of the underlying mechanism, the brazilwood had an impoverished richness of native pollinators and a significant reduction in the reproductive success in urban ecosystem, indicating an impairment in the pollination process. The viability of planting trees in tropical urban areas as an ex-situ conservation alternative for species obligatory dependent on cross-pollination, such as P. echinata, may be compromised.

Reproductive biology of the sausage tree (Kigelia africana) in Kruger National Park, South Africa

Kigelia africana has large flowers that are vertebrate pollinated and very large fruits that are likely to be vertebrate dispersed. Our field surveys of size–class distributions of K. africana in the southern Kruger National Park (KNP) suggest a lack of recruitment. This is possibly the result of a failure of mutualistic relationships with vertebrate dispersers and/or pollinators. Breeding system experiments indicated that K. africana is an obligate out-crosser. Despite being primarily adapted for bat pollination, in KNP that K. africana is presently mainly pollinated by a diversity of largely facultatively nectarivorous bird species. Fruit-set is high, although trees isolated by > 50 m were found to suffer depressed seed output. Our preliminary investigation of dispersal suggests that fruits are largely ignored and are thus weakly attractive to potential dispersers. Seedlings placed out in the field in KNP suffered high levels (> 50%) of mortality compared to 17.5% in control plots. This threefold difference is the result of herbivory over a 2-month period. In summary, the adult centric population structure is probably not because of pollen or seed limitation but may result from dispersal limitation or excessive herbivory.

A new spotted Chiloschista (Orchidaceae: Aeridinae) from Bhutan

A new species of Chiloschista from a restricted area in Bhutan is described and illustrated. It is compared with C. parishii from Myanmar and Thailand, which has similarly colored flowers and from which it differs by the larger flowers, 15–18 mm versus 8–10 mm, and the lack of a glandular and pubescent, erect and curved callus lobe inside the lip, which is generally seen in other similarly colored species of this genus.
 Key Words: Aeridinae, Bhutan, Himalaya, new Chiloschista, Orchidaceae, Vandeae

Floral adaptations of two lilies: implications for the evolution and pollination ecology of huge trumpet-shaped flowers.

Evolutionary transitions among floral morphologies, many of which provide evidence for adaptation to novel pollinators, are common. Some trumpet-shaped flowers are among the largest flowers in angiosperms, occurring in different lineages. Our goal was to investigate the role of pollinators in the evolution of these flowers using Lilium. We investigated floral traits and pollinators of L. primulinum var. ochraceum and L. brownii var. viridulum and reviewed reports of visitors to huge trumpet-shaped flowers. Using a published phylogeny of Lilium, we reconstructed ancestral floral morphological states in Lilium to elucidate the origins of trumpet-shaped lilies. Both lilies are largely self-incompatible and show floral syndromes indicative of hawkmoth pollination. The short trumpet-shaped lily can be pollinated by short-tongued (<40 mm) but not long-tongued hawkmoths (>65 mm), while the huge trumpet-shaped lily can be pollinated by both. A literature review including 22 species of trumpet-shaped flowers suggests that their pollinator guilds commonly include both short- and long-tongued moths. A phylogenetic reconstruction indicates that trumpet-shaped lilies possibly have multiple origins from tepal-reflexed ancestors, at least six of which have evolved huge flowers (>50 mm). Adaptation to short-tongued hawkmoths may have initiated the evolution of trumpet-shaped lilies. Huge trumpet-shaped lilies may have evolved as a response to selection by long-tongued hawkmoths, without excluding the short-tongued ones. This evolutionary pathway leads to a functionally more generalized pollination system instead of an increasingly specialized one and is not necessarily associated with pollinator shifts.

A new species of Acianthera (Pleurothallidinae, Orchidaceae) from Brazil

Acianthera sudae is newly described based on cultivated material from Brazil. It belongs to section Cryptophoranthae and differs from all others in this group by the larger flowers and sepals fused apically for more than half length, and a green-brown abaxial side of sepals with purple dots. Chromosome number (2n = 40) and genome size estimation (1C-value = 1.18 pg) is provided and its phylogenetic placement under the genus is supported with reconstruction of a molecular phylogeny using nuclear ribosomal ITS.

Vegetative and flowering behaviour of gerbera cultivars in different months under polyshadenet structure

Gerbera flower crop produces quality flowers under protected structure, which is highly costly and beyond the reach of common farmers. Hence, in the present investigation 18 cultivars of gerbera were evaluated under partially modified atmospheric structure i.e; polyshadenet structure with an objective to study the vegetative growth and flower production ability of the gerbera cultivars in different months of a year starting from July 2012 to June 2013 following completely randomized design with three replications. The results revealed that, among the 18 cultivars of gerbera, the cultivar ‘‘Cocharelle’’ putforth significantly maximum plant height in the months July (31.20 cm) and September (32.72 cm), 2012, January (33.74 cm) and February (34.34 cm), 2013. Whereas ‘‘Silvester’’ in the months August (32.33 cm), October (30.17 cm), November (33.86 cm) and December (30.94 cm), 2012 and the cultivar ‘‘Local Red’’ in the months March (32.14 cm), May (28.87 cm) and June (31.01 cm), 2013. The cultivar ‘Improved Pink’ produced significantly maximum number of leaves/plant (50.11) in the month of April, 2013, the cultivar ‘‘Acadia’’ from July to September 2012, and ‘Improved Pink’ enhanced the number from October 2012 to June 2013. The cultivar ‘‘Acadia’’ was found to be high suckering one, producing more suckers i.e; 7.20 in the month of March 2013 and remained constant up to June 2013. The other high suckering cultivars were ‘Improved Pink’, ‘‘Local Red’’, ‘‘Kayak’’, ‘‘Shimmer’’, ‘‘Destina’’ and ‘‘Cocharelle’’. Cultivar ‘‘Cocharelle’’ was highly floriferous cultivar producing more flowers/plant being maximum (3.16) in the month of January, 2013 followed by ‘Improved Pink’, ‘‘Local Red’’, ‘‘Molibu’’, ‘‘Dune’’, ‘‘Destina’’, ‘Sivester’, ‘Acalia’, ‘‘Shimmer’’, ‘‘Kayak’’ and ‘Goliath’. The cultivar ‘Goliath’ recorded significantly longer stalk (59.19 cm) in the month of January 2013 and the other cultivars with longer stalks were ‘‘Cocharelle’’ (53.00 cm), ‘‘Silvester’’ (50.19 cm), ‘‘Local Red’’, ‘‘Shimmer’’, ‘‘Pink Elegance’’, ‘‘Destina’’, ‘‘Dune’’, ‘Brilliance’, ‘Sunway’, ‘Dalma’, ‘‘Molibu’’. Larger flower diameter (11.45 cm) was recorded in ‘Goliath’ in January 2013. The other cultivars producing larger flowers were ‘Shimmer’ (10.92 cm), ‘‘Cocharelle’’ (10.84 cm), ‘‘Local Red’’ (10.10 cm), ‘‘Molibu’’ (9.29 cm), ‘‘Dune’’ (9.22 cm) and ‘Casiana’ (9.10 cm). The cultivars with prolonged blooming period were ‘‘Molibu’’, ‘Rosalin’, ‘‘Cocharelle’’, ‘‘Local Red’’, ‘‘Acadia’’ and ‘‘Destina’’ being maximum (13.37 days) in ‘‘Molibu’’. Hence most promising cultivars suitable for cut flower purpose under polyshadenet structure are ‘‘Cocharelle’’, ‘‘Molibu’’, ‘‘Dune’’, ‘Goliath’, ‘‘Shimmer’’, ‘‘Silvester’’ and ‘‘Destina’’. The period from October 2012 to March 2013 was found to be most congenial period for yield and quality of the cut flowers.

A synopsis of Thyrsacanthus (Acanthaceae) in Argentina and Paraguay, with notes on generic delimitation, a new combination, and lectotypifications

A taxonomic synopsis of the members of the re-circumscibed Thyrsacanthus from Argentina and Paraguay is presented. Two species are recognized for the region, T. boliviensis and T. sulcatus. The latter is a new combination here proposed, based on Jacobinia sulcata (until now treated in Carlowrightia), that is corroborated by morphological data and geographic distribution as well as molecular phylogenetic information. Thyrsacanthus sulcatus is clearly distinguished from T. boliviensis by its small, white, lilac or pale blue, presumably psychophilous flowers with a narrow tube, instead of the large and red ornithophilous flowers with a tube that widens to the throat, which is typical of other species of Thyrsacanthus. Differences between the re-circumscribed Thyrsacanthus and other genera of the Tetramerium lineage to which it belongs are discussed, and references to additional genera of Acanthaceae that present similar wide diversification in floral morphology are noted. The synopsis includes a key, full synonymies, descriptions, illustrations, distributions, and lists of representative specimens. Lectotypifications are provided for the following names: Anisacanthus malmei, Dianthera sulcata, Jacobinia caducifolia, Schaueria caduciflora, and Siphonoglossa gentianifolia.

Sebaea solaris (Gentianaceae), a new species from the Western cape of South Africa

Sebaea solaris (Gentianaceae) is here described as a new species from the Overberg region, Western Cape, South Africa. This new species is at first glance very distinct from all others in the genus mainly due to its relative large yellow flowers of c. 2.5 cm diameter with oblanceolate to obdeltoid erose corolla lobes. The petal ornamentation with several orange lines indicating the flower centre (versus two lines per petal for a few other Sebaea species) and a conspicuous undulated calyx wing are also unique in the genus. Furthermore, the position of large secondary stigmas above the middle of the style (versus at the base of the style for its morphologically closest relative: S. exacoides) possibly indicates differences in pollination strategies.

Reproductive assurance weakens pollinator-mediated selection on flower size in an annual mixed-mating species.

In animal-pollinated plants, direct and indirect selection for large and small flowers in predominantly outcrossing and selfing species, respectively, is a common consequence of pollen limitation (PL). However, many hermaphroditic species show a mixed-mating system known as delayed selfing, which provides reproductive assurance (RA) only when outcrossing is not realized. Although RA is expected to reduce pollinator-mediated selection towards larger flowers, the consequences of delayed selfing for selection on flower size in mixed-mating species remain overlooked. We investigated whether RA weakens selection on flower size in Tuberaria guttata, a mixed-mating annual herb. We related pollinator visitation rates to flower size and measured seed production in emasculated, hand cross-pollinated and intact (control) flowers in three natural populations. For each population, we estimated variation in PL and RA across individuals differing in flower size and phenotypic selection on this trait. Pollinator visitation increased and RA decreased with flower size in all populations. Increasing RA diminished but did not fully alleviate PL, because of early-acting inbreeding depression. In the least-visited and most pollen-limited population, RA increased seed production by >200 %, intensely counteracting the strong pollinator-mediated selection for larger corollas. In the most-visited population, however, RA increased seed production by an average of only 9 %. This population exhibited the largest fraction of individuals that showed a decrease in seed production due to selfing and the weakest pollinator-mediated selection on flower size. The results suggest that the balance between the extent of RA and outcrossing contributes to determine flower size in mixed-mating systems. Pollinator-mediated selection favours larger flowers by increasing outcrossed seeds, but the benefits of RA greatly lessen this effect, especially under severe conditions of pollen limitation. Our findings also indicate that a mixed-mating system can represent an 'evolutionary trap' under an adequate pollinator supply.

Clematismae (Ranunculaceae), a new species of C.sect.Meclatis from Xinjiang, China.

Clematismae Z.Z.Yang & L.Xie, a new species of Ranunculaceae from Xinjiang, China, is described and illustrated. The new species is morphologically similar to C.orientalis and C.glauca but can be distinguished for being a less hairy plant (hairy in C.orientalis), often 2-ternate leaves (1–2-pinnate for C.orientalis and C.glauca), lanceolate to linear-lanceolate leaflets (elliptic or ovate in C.glauca), larger flowers (smaller flower in C.orientalis) and narrowly lanceolate sepals with acute to slightly attenuate apex (narrowly oblong sepals in C.orientalis and ovate to broadly lanceolate sepals in C.glauca). The new species is endemic to the southern slope of North Tianshan Mountain in Central Xinjiang. The conservation status of the species is also discussed.