ISSN:
1615-6110
Keywords:
Angiosperms
;
Boraginaceae
;
Rochelia
;
Rochelia disperma
;
Gynoecial development
;
fruit development
;
pseudomonomery
;
systematics
;
evolutionary trends
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The ontogeny of the gynoecium ofRochelia disperma has been investigated by LM and SEM. From the floral apex only one carpel primordium arises abaxially and eventually shifts into a subterminal position. Neither an initial stadium of a second carpel nor an adaxial vascular strand in gynobase and style could be observed. InR. stylaris two vascular strands run through the style and two undifferentiated lobes in adaxial position may be regarded as rudimentary mericarps. Only from comparison with related taxa the conclusion can be drawn thatRochelia is really pseudomonomerous, more so inR. disperma than inR. stylaris. The primary gynoecial bulge splits up into three parts inR. disperma: style/stigma, nutlets with gynobase, and disc. While the mericarps originate in mostBoraginoideae from the symplicate region and the ascidiate one is restricted to the very basal parts, inR. disperma the ascidiate part extends and forms the nutlets. The hood-shaped mouth of the carpel (the plicate zone) is closed to a triangular slit in lateral position, the stigma. The nutlets are triangular with broad base and do not surround the adaxial part of the gynobase inR. disperma, R. persica, R. bungei, R. stylaris, andR. macrocalyx. In contrast,R. peduncularis, R. cardiosepala, andR. cancellata have nutlets clasping the gynobase; they may be more closely related than was assumed up to now. The glochids ofRochelia are fascicled unicellular hairs (with different shapes) and not emergences as in theCynoglosseae. There is an evolutionary trend towards fruit formation with only one mericarp, especially inR. disperma.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00984059
