Floral anatomy points to autogamy as a possible evolutionary path in Elatinaceae (Malpighiales)

Unravelling the Homology between Calycine Glands in Malpighiales: New Data from Basal Malpighiaceae

“…Furthermore, the initial stages of elaiophore ontogeny and vascular sharing between adjacent sepals align with the vestigial existence of a gamosepalous calyx [ 45 ]. The occurrence of a gamosepalous calyx connects Malpighiaceae to other families of Malpighiales that also have connate sepals, such as Caryocaraceae [ 4 , 46 ], Elatinaceae [ 39 ], Euphorbiaceae [ 47 ], and Rhizophoraceae [ 4 ].…”

“…When considering the occurrence of nectaries in vegetative organs (EFNs) and calycine nectaries within a phylogenetic framework of Malpighiales, it becomes apparent that, for parsimony, the most proximal relationship likely exists between elaiophores and sepal nectaries. The presence of calycine glands on the abaxial surface of the sepals is reported for the following families of Malpighiales: Euphorbiaceae [ 29 , 30 , 57 ], Linaceae [ 31 ], Passifloraceae [ 32 , 33 , 34 ], Humiriaceae [ 35 , 36 ], Chrysobalanaceae [ 37 , 38 ], Caryocaraceae [ 4 , 40 , 41 , 56 ], and Elatinaceae [ 39 , 42 ]. Additionally, evidence of secretory structures was also observed on the margins of the sepals of Bergia perennis and the apex of the sepals of Elatine gratioloides [ 39 ].…”

“…Note that calycine nectaries are not described for clade 2. Superscript numbers after the genera whose flowers are illustrated indicate the data source: 1 Farias et al [30]; 2 Almeida [29]; 3 Narayana and Rao [31]; 4 Knapp and Mallet [32]; 5 Wurdack and Zartman [36]; 6 Prance and White [37]; 7 Niedenzu [42]; 8 Bonifácio et al [39]; 9 Castro et al [24]; 10 This work; 11 Oliveira [40]. Abbreviations: cn, calycine nectary; cn*, calycine nectary not confirmed by histochemical tests; el, elaiophore.…”

“…The presence of calycine glands on the abaxial surface of the sepals is reported for the following families of Malpighiales: Euphorbiaceae [29,30,57], Linaceae [31], Passifloraceae [32][33][34], Humiriaceae [35,36], Chrysobalanaceae [37,38], Caryocaraceae [4,40,41,56], and Elatinaceae [39,42]. Additionally, evidence of secretory structures was also observed on the margins of the sepals of Bergia perennis and the apex of the sepals of Elatine gratioloides [39]. Consequently, the occurrence of calycine glands (without specifying the type of secretion) encompasses two of the three main lineages of Malpighiales, clades 1 and 3 of Xi et al [8].…”

Evolution of connective glands reveals a new synapomorphy for Malpighiaceae and the hidden potential of staminal glands for Malpighiales systematics

“… Malpighiaceae has already been the subject of staminal glands anatomical studies by several authors ( Possobom et al 2015 ; Arévalo-Rodrigues et al 2020 ; Avalos et al 2020 ; this study). On the other hand, Elatinaceae comprises only two genera, Bergia and Elatine , which were recently sampled in a comprehensive anatomical study by Bonifácio et al (2023) and seemed to present, indeed, eglandular stamens in most of its species, except for Elatine lindbergii Rohrb. These authors performed histochemical tests for E. lindbergii indicating the presence of phenolic compounds, but they failed to test the exudate of these glands for lipids.…”