Lagenandra Ovata (Araceae, Areae, Cryptocoryninae), a Strange Inflorescence

Lagenandra ovata (Araceae, Areae, Cryptocoryninae), a strange inflorescence

Introduction Previous studies The spathe The inflorescence of Lagenandra and Cryptocoryne is compartmentalized. The spathe forms a roof dividing the spathe In some members of the tribe Areae, such as Sauromatum and Arum, room into an upper chamber and a lower kettle, which encloses the entire inflorescence axis (spadix). Both upper The inner surface of the spathe is elaborated with rims, expanding to prominent emergences along differential odour production between the appendix of the inflorescence chamber and lower kettle are connected by a very narrow canal. the margins and at the base of the upper spathe chamber, on the roof. These emergences are axis and the space enclosed by the spathe base was found (Smith & secretory. Meeuse 1966, Chen & Meeuse 1971, Kite 1995). During early anthesis of Lagenandra ovata, the odour outside of the spathe and inside of the upper spathe chamber is like fish carrion or excrement. Inside the kettle, in contrast, the odour is sweet, like rotting fruits.

The sweet odour in the kettle originates from the male and the club-like, sterile flowers. The carrion-like odour is produced by the spathe. The female flowers produce no odour.

The carrion-like odour is correlated with a water-like, clear liquid secreted on the inner surface of the spathe. Thus, the spathe has taken over functions of the appendix in other member of the Areae.

Basal inflorescence axis of Inflorescence of Arum Sauromatum guttatum with maculatum with an exposed yellow male flowers (upper appendix of the part of the picture) and inflorescence axis. yellow olfactory clubs above the female flowers. Along the axis of the inflorescence, the functions of the In some members of Cryptocoryne (here C. usteriana), some parts of the spathe are conspicuously flowers are strictly specialised, yellow. In Lagenandra and C. ciliata (Vogel 1963) the identical regions are osmophores. as it is common in the tribe Areae: A sterile appendix, hidden by the valvule, on top of a zone of male flowers, Cryptocoryne The canal (arrow) is limited by the reduced to sessile anthers, a usteriana with yellow external wall of the spathe, and by sterile portion, and at the very The male flowers margins atop of the an inner fold of the spathe, the base, a cluster of female flo- spathe. valvule, enclosing the apical part of wers, reduced to monomerous They are secretory. the inflorescence axis. gynoecia.

The sterile clubs

Atop of the cluster of female flowers, a whorl of sterile, club-shaped organs is found. The features of the The valvule of Cryptocoryne clubs are identifying them as staminodial flowers, as presented in a talk of this meeting. usteriana is yellow and secretory. In Cryptocoryne (C. usteriana), the rim of the anthers is papillose.

The male flowers bear a rim The rim is stained by neutral and elongate tubular stomia. red and thus secretory (here C. usteriana).

There are also acute papillae These clubs are yellow, they along inner epidermis of the are stained by neutral red, spathe in several members of ...... they are biparted and The longitudinal section of a Cryptocoryninae. papillose, like male flowers. club. Cells of secretory tissue are dark purple.

The secretory function of The tissue of the stomia stomia and rim is shown by disintegrates parallel to odour tiny liquid droplets secreted release. This leads to tubular Remaining questions by the rim, while the tissue stomia, through which the At the end of the stomia the of the rim disintegrates. pollen is released (here pollen and its mucilaginous matrix form droplets. C. usteriana). 1) Is the osmophoric function in aroids generally correlated with the onto- genetic program of male flowers ? (Barabé & Bertrand 1996, Boubes & Barabé 1996) Literature cited The Author

Kite, G.C. 1995. Barabé, D. & Bertrand, Ch. 1996. 2) What is the significance of the yellow colour in anthers, sterile clubs, some The floral odour of Arum maculatum. Matyas Buzgo Organogénie florale des genres Culcasia et Cercestis (Araceae). Biochem. Syst. Ecol. 23: 343-354. Can. J. Bot. 74: 898-908. spathe margins and valvules in respect to the function of odour Institut für Systematische Botanik der Unibersität Zürich Smith, B.N. & Meeuse, B.J.D. 1966. Boubes, Ch. & Barabé, D. 1996. production ? (Vogel 1963) Zollikerstrasse 107 Production of volatile amines and skatoles at anthesis in some Développement de l'inflorescence et des fleurs du Philodendron CH-8008 Zürich arum lily species. acutatum Schott (Araceae). Switzerland Plant Physiol. 41: 343-347. Can. J. Bot. 74: 909-918. fax: +41-(0)1-385 44 03 [email protected] Vogel, S. 1963. Chen, J. & Meeuse, B.J.D. 1971. Duftdrüsen im Dienste der Bestäubung: Über Bau und Funktion Production of free indole by some arum lilies. der Osmophoren. Acta Bot. Neerl. 20: 627-635. Abh. Akad. Wiss. Lit. Mainz, Math.-Naturwiss. Kl. 10: 559-763.