Convolvulaceae

Herbs or shrubs, sometimes parasitic, usually with twining stems, occasionally prostrate or creeping, or erect, very rarely trees, often with milky juice. Leaves mostly spirally arranged, in parasitic species absent or nearly so, usually petioled; petiole sometimes with extra-floral nectaries. Stipules absent, pseudostipules (leaves of axillary shoot) rarely present. Inflorescences mostly cymose, one- to many-flowered, with mostly opposite or subopposite bracts at the base of the cymes or under the solitary flowers; rarely racemose. Flowers generally hermaphrodite, actinomorphic, rarely slightly zygomorphic, usually 5-merous, rarely 4-merous, various in size and colour, often showy. Sepals usually free, imbricate, with quincuncial aestivation, often persistent, sometimes accrescent in fruit. Corolla sympetalous, of various shapes, often funnel-shaped or campanulate, more rarely rotate, salver-shaped or urceolate; the limb nearly entire or more or less deeply lobed, often contorted-plicate in bud, or valvate or induplicate-valvate. Stamens isomerous, alternating with the corolla-lobes, adnate to the corolla, with usually slender, often filiform filaments and introrse or laterally and longitudinally dehiscing anthers. Pollen smooth or spinulose. Disk mostly present, annular or cupular. Ovary superior, mostly of 2 carpels, 2- or 1-celled, sometimes 4-celled by development of accessory partitions, rarely of 3 carpels and 3-celled; ovules 2 in each carpel, sessile, erect, anatropous. Style 1, often filiform, simple or forked, or 2 free styles, rarely very short or absent. Stigma entire or 2-lobed, rarely 3-lobed, or stigmas 2-4, of various shape, globular or ellipsoid to filiform, sometimes applanate, rarely peltate, kidney-shaped, conical or funnel-shaped. Fruit a capsule dehiscing by valves or circumscissile or irregularly dehiscing, rarely a berry or nut-like. Seeds as many as ovules or fewer; endosperm cartilaginous; cotyledons generally folded, sometimes obscure or absent. Distr. Ca 55 genera, with ca 1650 spp., widely distributed in the tropical, subtropical and temperate regions of both hemispheres; the greater part of the species in the tropics and subtropics of America and Asia. The larger genera Cuscuta (ca 165 spp.), Convolvulus (ca 250 spp.) and Ipomoea (ca 500 spp.) nearly throughout the range of the family but Convolvulus more in the temperate parts and Ipomoea more in the tropics and subtropics. Other large genera as Evolvulus (ca 100 spp.) and Jacquemontia (ca 120 spp.) nearly confined to America. Argyreia (ca 90 spp.) confined to tropical Asia. Malaysia, and a single sp. in Australia, and Merremia (ca 80 spp.) circumtropical. Several monotypic or small genera in E. Africa, Madagascar, and Australia

Regularized parametric survival modeling to improve risk prediction models

We propose to combine the benefits of flexible parametric survival modeling and regularization to improve risk prediction modeling in the context of time-to-event data. Thereto, we introduce ridge, lasso, elastic net, and group lasso penalties for both log hazard and log cumulative hazard models. The log (cumulative) hazard in these models is represented by a flexible function of time that may depend on the covariates (i.e., covariate effects may be time-varying). We show that the optimization problem for the proposed models can be formulated as a convex optimization problem and provide a user-friendly R implementation for model fitting and penalty parameter selection based on cross-validation. Simulation study results show the advantage of regularization in terms of increased out-of-sample prediction accuracy and improved calibration and discrimination of predicted survival probabilities, especially when sample size was relatively small with respect to model complexity. An applied example illustrates the proposed methods. In summary, our work provides both a foundation for and an easily accessible implementation of regularized parametric survival modeling and suggests that it improves out-of-sample prediction performance

Flore de la Nouvelle-Calédonie : 26. Cunoniaceae

La flore de Nouvelle-Calédonie est mondialement connue pour son exceptionnelle richesse avec quelque 3 371 espèces indigènes de plantes vasculaires dont les 3/4 sont endémiques du territoire. L'originalité de cette flore est remarquable, tant aux niveaux taxonomiques supérieurs (une centaine de genres et trois familles endémiques) que par la concentration de lignées primitives ou inhabituelles tel un conifère parasite, ou de plantes accumulatrices de métaux lourds. Des espèces restent encore à décrire et des programmes de recherche sont nécessaires pour mieux comprendre l'origine de cette diversité et contribuer à sa préservation. Ce nouvel ouvrage de la Flore de Nouvelle-Calédonie, publié conjointement par le Muséum national d'Histoire naturelle et l'Institut de Recherche pour le Développement, est une monographie sans précédent des Cunoniaceae de Nouvelle-Calédonie. Cette famille de près de 350 espèces, de répartition essentiellement australe, est particulièrement bien représentée sur le Territoire, où ont été recensées 91 espèces, toutes endémiques, réparties en sept genres : Codia, Cunonia, Geissois, Hooglandia, Pancheria, Spiraeanthemum, Weinmannia. Après une présentation générale de la famille, la description de chaque genre et des espèces qu'il comporte est accompagnée de clés d’identification nombreuses et illustrées, de cartes de répartition, de dessins au trait. L'ensemble est enrichi par de nombreuses photographies. Aussi détaillée qu'attractive, cette flore restera la référence internationale sur les Cunoniaceae de Nouvelle-Calédonie pendant de nombreuses années

Distribution maps of Pacific plants

Name: Campynema Labill, Nov. Holl. Pl. Sp. 1 (1805) 93, t. 121. Family: Amaryllidaceae