In the Fibonacci-type phyllotaxis, there are always contact parastichies between leaves that are x, y and z plastochrones apart, with x, y and z being consecutive members of the Fibonacci sequence: 3, 5, 8, 13, 21, … ( Rutishauser and Peisl, 2001). A contact parastichy is the curved line by which contacting leaves are linked together (see Fig. 1B). In a densely packed shoot tip, young leaves are in contact with certain other leaves. The time interval between the initiation of two consecutive primordia at the shoot apical meristem (SAM) is termed plastochrone. Along the ontogenetic spiral consecutive primordia are separated by the above-mentioned divergence angle. For the Fibonacci-type phyllotaxis this angle is around 137° (120–144°, see Rutishauser, 1998). The divergence angle is the stem sector enclosed by two consecutive leaves or leaf primordia along the ontogenetic spiral (see Fig. 2A). One is the measurement of the divergence angle between two consecutive leaves, and the second is the observation of the contact parastichies. There are two ways to detect such a pattern. ( Cutter, 1961 Grob et al., 2006).Īmong vascular plants, the most frequent phyllotaxis is the Fibonacci pattern. vulgaris, occupy leaf sites, similar to what is known from Nymphaea spp. In opposition to this view, Raju (1969) thought that the flowers in Pinguicula, especially P. Casper (1966), for example, considered that the flowers of Pinguicula arise from the axils of rudimentary leaves, while the rosettes themselves show monopodial construction. moranensis have been discussed by various authors. This species, originating from Mexican Highlands, Guatemala and El Salvador, belongs to the tropical growth form, flowering nearly year-round ( Goebel, 1891 Zamudio and Rzedowsky, 1991 Barthlott et al., 2004).īranching patterns of flower-producing leaf rosettes in P. longicaudata) is a well-known flycatcher plant in greenhouses. Furthermore, Pinguicula is one of the few genera in eudicots where monocotyledony has been observed ( Troll, 1937 Casper, 1966). Although they all have roots, Pinguicula roots often lack rootcaps and are unbranched ( Rutishauser and Isler, 2001). Besides their carnivory, there are other features that make them of particular interest for morphologists. a winter bud, from which the new plant will grow in the coming spring) and a tropical one (winter rosette with usually narrower leaf blades) ( Casper, 1966). There are two distinct growth-forms in the genus, a temperate one (over-wintering in a hibernaculum, i.e. The hygrophilous genus Pinguicula is characterized by a basal rosette of more or less broadly ovate leaves that, by means of secretory glands, capture and digest insects ( Casper, 1966 Legendre, 2000). Jobson et al., 2003 Müller et al., 2004) more meaningful. Morphological analyses of the Lentibulariaceae are badly needed in order to make molecular phylogenies (e.g. The vegetative bauplans of the genera Pinguicula (86 spp.), Utricularia (including Polypompholyx, 220 spp.) and Genlisea (21 spp.) are still not yet properly understood. The studies of Goebel (1891, 1928–1933) and Lloyd (1942) have already provided interesting insight into the developmental morphology of various Lentibulariaceae. The family appears in the Lamiales where its final position is yet to be determined ( Albert et al., 1992 Bremer et al., 2002 Müller et al., 2004). Among the carnivorous family Lentibulariaceae, Pinguicula is the most basal genus ( Jobson et al., 2003).
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