Gynoecium with carpel dimorphism in Tricomaria usillo, comparison with other genera of the Carolus clade (Malpighiaceae)
We analyzed the gynoecium morphology and anatomy of Tricomaria usillo in young and mature flowers from diverse populations in order to analyze the differentiation of structure and function of the parts of the carpel. We also aimed to find the potential pollinators and associate the morphology of the gynoecium with its role. We compare the characteristics of the gynoecium of T. usillo and discuss the carpel dimorphism with other genera within the Carolus clade in relation with their pollination syndromes. Carpels were processed according to classic techniques for scanning electron microscopy and bright field microscopy. We conducted field observation in different populations of T. usillo and captured the insects that were identified to specific level. The gynoecium of T. usillo shows inter-population and intra-individual variability. Some have three well-developed carpels, while most of them present two posterior carpels with differentiated styles and stigmas and the anterior one with a shorter style with or without stigma. The ovary has three locules with one ovule each. A compitum is formed and all ovules may be fecundated. However, fruits have generally one seed that develops in the anterior locule. Centris brethesi is the potential pollinator. The gynoecium of T. usillo reflects part of the variation in the carpel dimorphism that probably arose in the branch of the Carolus clade, and evolved in diverse ways in the lineages of this group. Tricomaria usillo seems to represent a recent transition towards reaching a stable form of carpel dimorphism and definitive division of labors of the carpels.
KeywordsAnatomy Compitum Pollination Style Stigma
We thank G. Zarvlasky for technical assistance; A. Calviño for providing material from La Cantina, Córdoba; R. Saurral for the revision of the English language; and two anonymous reviewers.
This work was funded by a research grant from Agencia Nacional de Promoción Científica y Tecnológica, grant number PICT 2013-1867 to S. Aliscioni, Consejo Nacional de Investigaciones Científicas y Técnicas, grant number PIP 11220110100312, and Universidad de Buenos Aires, grant number UBACyT 20020130200203BA to J. P. Torretta. Sandra Aliscioni, Marina Gotelli and Juan Pablo Torretta are affiliated with Consejo Nacional de Investigaciones Científicas y Técnicas, and Universidad de Buenos Aires, Argentina.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. This article does not contain any studies with human participants performed by any of the authors.
- Aliscioni SS, Torreta JP (2017) Malpighiaceae. Pages 163–205 in Flora Argentina, eds. Zuloaga FO, Belgrano MJ, Vol 17, Sigma, Buenos AiresGoogle Scholar
- Anderson WR (1990) The origin of the Malpighiaceae. The evidence from morphology. Mem New York Bot Gard 64:210–224Google Scholar
- Anderson WR, Anderson C, Davis CC (2006) Malpighiaceae. http://herbarium.lsa.umich.edu/malpigh/index.html [January 2019]
- Arumuganathan K, Udaiyan K, Sugavanam V (1994) Structure and ontogeny of floral and extrafloral nectaries in Hiptage benghalensis (L.) Kurz (Malpighiaceae). Adv Plant Sci 7:105–111Google Scholar
- Arumugasamy K, Inamdar JA, Subramanian RB (1989) Structure, ontogeny and secretion of oil secreting glands in Hiptage acuminate Wall. Curr Sci 58:260–261Google Scholar
- Baum H (1948) Postgenitale Verwachsung in und zwischen Karpell- und Staubblattkreisen. Sitz ber Österr Akad Wiss Math-Natur-wiss Kl, Abt1 157:17–38Google Scholar
- Launert E (1968) Malpighiaceae. Flora of tropical East Africa. 24 pp.Google Scholar
- Niedenzu FJ (1928) Malpighiaceae Pars I Pages 67–84 in Das Pflanzenreich, ed. A Engler. IV, 141Google Scholar
- Thiers B (2014) Index Herbariorum: a global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. Available from: http://sweetgum.nybg.org/ih (accessed December 2018)
- Vogel S (1990) History of the Malpighiaceae in the light of pollination ecology. Mem New York Bot Gard 55:130–142Google Scholar
- Zarlavsky GE (2014) Histología Vegetal: técnicas simples y complejas. Sociedad Argentina de Botánica, Buenos Aires, ArgentinaGoogle Scholar