Hiptage is an Asia-endemic genus of Malpighiaceae currently placed in the tetrapteroid clade, representing one of the seven inter-continent dispersions from New to Old World. A molecular phylogeny based on sequences of the internal transcribed spacer (ITS) region was recovered for the first time for the genus. Our results showed that the most recent common ancestor of Hiptage probably originated in the South Indo-China Peninsula and diversified in this region. Based on phylogenetic evidence and relevant morphological traits, we propose a new species; Hiptage incurvatum is characterised by mericarps with arcuate anterior lateral wings, two large glands on the dorsal sepals, and small glands on the remaining sepals. The new species is from Mt. Cangshan, Dali City (25°35'N, 100°02'E) in North Yunnan, Southwest China and is notable for its occurrence at high altitude, 1400 m (the highest distribution currently known for the genus). The implications of this unusual species for the dispersal and evolution of the genus are discussed.

Samara (winged fruit) can be dispersed easily by wind and may be a crucial factor for angiosperm spread and diversification. In a narrow sense, a samara is an indehiscent dry fruit with wing(s) developed from fruit pericarp, while in a broad sense samaras also include all winged fruits with wings developed from both pericarp and perianth or bracts. According to the wing shape and growth patterns of samaras, we divided samaras into six types, i.e. single-winged, lanceolate-winged, rib-winged, sepal-winged, bract-winged, and perigynous samaras. Perigynous samaras can be further classified into two forms, i.e. round-winged and butterfly-winged samaras. Accordingly, the aerodynamic behavior of samaras can be classified into five types, autogyro, rolling autogyro, undulator, helicopter, and tumbler. The rib-winged and round-winged samaras can be found in Laurales, a basal angiosperm, and may represent the primitive type of early samaras. In the derived clades, samaras evolved enlarged but unequal wings and decreased wing loading (the ratio of fruit weight to wing size), which is likely an adaptation to gentle wind and secondary dispersal through water or ground wind. The wings of some samaras (such as sepal-winged and bract-winged samaras) may have multiple functions including wind dispersal, physical defense for the seeds, and adjust seed germination strategy. The pantropical family Malpighiaceae is extraordinarily rich in samara types, which is likely related to its multiple inter-continent dispersal in history, which is known as "Malpighiaceae Route". Therefore, Malpighiaceae can be used as a model system for the studies on samara adaptation and evolution. We identified the following issues that deserve further examination in future studies using both ecological and evo-devo methods: 1) the adaption of different types of samaras in dispersal processes, 2) the molecular and developmental mechanism of sepal-and bract-wings, and 3) the evolution of samara types and their effects on angiosperm diversification.

ReferencesThe chloroplast as a regulator of Ca 2+ signallingMany of the attributes associated with multicellular plant life, including a sedentary habit, a decentralized organization, signalling in the absence of a nervous system and a plastic developmental programme, can be attributed to the autotrophism facilitated by the chloroplast. In this issue of New Phytologist, ) identify a new role for the chloroplast in Ca 2+ signalling, which suggests that the plastid can exert control over signalling events in the cytosol. (Han et al., 2003)). In Arabidopsis, CAS is expressed in the shoots and is found in guard cells (Han et al., 2003). CAS binds Ca 2+ at the Nterminus with low affinity and high capacity (Han et al., 2003). CAS was first proposed to be a plasma membrane receptor that senses [Ca 2+ ] ext (Han et al., 2003 (Allen et al., 1999; Staxén et al., 1999; Weinl et al.).The sensing, by CAS, of changes in [Ca 2+ ] stroma could potentially affect the release or uptake of Ca 2+ by the chloroplast. It is possible that the plastids act either as Ca 2+ stores that release Ca 2+ into the cytosol or as a Ca 2+ buffer that removes Ca 2+ from the cytosol following stimulation. The plastids could have a similar role to mitochondria in Ca 2+ signalling. In mammals, mitochondria act as Ca 2+ buffers that take up Ca 2+ from the cytosol following release from the endoplasmic reticulum (ER) and the sarcoplasmic reticulum (SR). The tight coupling between ER/SR release and mitochondrial uptake has profound effects on localized [Ca 2+ ] cyt dynamics, and mitochondria also contain a pool of releasable Ca 2+ (Hetherington & Brownlee, 2004 (Miller & Sanders, 1987; Sai & Johnson, 2002; Johnson et al., 2006). Chloroplasts take up Ca 2+ in the light (Miller & Sanders, 1987; Xiong et al., 2006), and CASTOR and POLLUX are required for nodulation (NOD) factor-induced Ca 2+ oscillations in root hairs of Lotus japonicus and are predicted to encode plastid-localized ion channels of unknown selectivity (Imaizumi-Anraku et al., 2005). Similarly, the pea PPF1 protein localizes to the chloroplast, delays flowering when expressed in Arabidopsis and is capable of carrying Ca 2+ currents (Wang et al., 2003).In addition to plastid regulation of [Ca 2+ ] cyt , there are dark-induced increases in [Ca 2+ ] stroma that can persist with a circadian rhythm in constant dark (Sai & Johnson, 2002 ( Johnson et al., 1995). Sai & Johnson (2002) proposed that the thylakoid is a dark-dischargeable Ca 2+ store that releases into the stroma. The thylakoid is suggested to be filled with Ca 2+ from the cytosol via the stroma as a result of the action of a Ca 2+ /H + antiporter acting in the light (Ettinger et al., 1999). Lengthening the light period appears to increase the amount of Ca 2+ stored in the thylakoid because dark-induced discharge is increased with longer periods of light (Sai & Johnson, 2002).It is not known if CAS affects the daily dark-induced increase in [Ca 2+ ] stroma but CAS antisense reduces the amplitude of daily oscillations of [...

Based on an updated taxonomy of Gesneriaceae, the biogeography and evolution of the Asian Gesneriaceae are outlined and discussed. Most of the Asian Gesneriaceae belongs to Didymocarpoideae, except Titanotrichum was recently moved into Gesnerioideae. Most basal taxa of the Asian Gesneriaceae are found in the Indian subcontinent and Indo-China Peninsula, suggesting Didymocarpoideae might originate in these regions. Four species diversification centers were recognized, i.e. Sino-Vietnam regions, Malay Peninsula, North Borneo and Northwest Yunnan (Hengduan Mountains). The first three regions are dominated by limestone landscapes, while the Northwest Yunnan is well-known for its numerous deep gorges and high mountains. The places with at least 25% species are neoendemics (newly evolved and narrowly endemic) which were determined as evolutionary hotspots, including Hengduan Mountains, boundary areas of Yunnan-Guizhou-Guangxi in Southwest China, North Borneo, Pahang and Terengganu in Malay Peninsula, and mountainous areas in North Thailand, North Sulawesi Island. Finally, the underlying mechanisms for biogeographical patterns and species diversification of the Asian Gesneriaceae are discussed.

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