03217nas a2200181 4500008004100000022001400041245008900055210006900144300001200213490000800225520262500233100001902858700002602877700002602903700002402929700002202953856006002975 2018 eng d a1058-589300aGynoecium and fruit development in Heliotropium sect. Heliothamnus (Heliotropiaceae)0 aGynoecium and fruit development in Heliotropium sect Heliothamnu a275-2860 v1793 a
Premise of research. Heliotropiaceae (Boraginales) are morphologically readily defined by their peculiar floral morphology, especially their conspicuous stigmatic heads. Heliotropium L. is the largest genus of the family, and within this genus, Heliotropium sect. Heliothamnus I.M. Johnst. is the sister clade to the remaining Heliotropium species. Earlier studies have pointed out a series of gynoecium morphological features of H. sect. Heliothamnus (e.g., a seemingly persisting columella and a gynobasic style) that are not present in the remainder of the genus but are paralleled in the closely related family Boraginaceae s. str. However, a detailed, ontogenetic understanding of the gynoecium and fruit morphology of H. sect. Heliothamnus has not been achieved.Methodology. Here we describe the development of the gynoecium and fruit of H. sect. Heliothamnus using SEM, light microscopy, and high-resolution X-ray computed tomography.Pivotal results. The two-carpellate, syncarpous gynoecium is characterized by four functional subunits: a nectary, an ovary with four mericarpids, a style, and a stigmatic head. All four subunits differentiate simultaneously. At first, the stigmatic head is formed, followed by the style and the gynoecial nectary disc, which is then followed by the onset of the development of mericarpids. After anthesis, the size of the mericarpids increases and their surface sculpturing differentiates. All four mericarpids are laterally attached to each other around the central tissue of the ovary, which disintegrates during fruit development. The ovary is lobed and divided through septa between and within the carpels. After detachment, the contact areas between the mericarpids leave scars, which resemble the cicatrix of the Boraginaceae s. str. In contrast to the Boraginaceae s. str., the whole gynoecium is dispersed.Conclusions. Mericarpid development in Heliotropium sect. Heliothamnus follows a different developmental trajectory than in Boraginaceae s. str. Individual nutlets separate in two steps and not simultaneously. A tissue in the center of the ovary is present in immature fruits of H. sect. Heliothamnus, but it disintegrates during maturation and is absent in mature fruits. It is not structurally equivalent to the persisting columella characterizing the fruit of Boraginaceae s. str. The style is not gynobasic but rather distally attached to the mericarpids. The schizocarpic mericarpids in Heliotropium sect. Heliothamnus are thus not structurally correspondent to the eremocarps of the Boraginaceae s. str., as previously suggested.
1 aJeiter, Julius1 aStaedler, Yannick, M.1 aSchönenberger, Jürg1 aWeigend, Maximilian1 aLuebert, Federico uhttp://www.journals.uchicago.edu/doi/abs/10.1086/69621901453nas a2200205 4500008004100000022001400041245004900055210004900104300001400153490000700167520089000174653001701064653001601081653001701097653001501114653001301129653001701142100002201159856006601181 2017 eng d a1851-237200aLos géneros de Heliotropiaceae en Argentina0 aLos géneros de Heliotropiaceae en Argentina a787–7960 v523 aLa delimitación genérica dentro de Heliotropiaceae ha sufrido cambios en el último tiempo que no son recogidos en publicaciones taxonómicas recientes sobre el grupo en Argentina. En este trabajo se actualiza la taxonomía de los géneros argentinos de Heliotropiaceae y se enumeran las especies aceptadas en cada uno de ellos. Se proporciona una breve descripción para cada género y una clave para diferenciarlos. Los géneros de Heliotropiaceae aceptados en este trabajo son Euploca, Heliotropium, Ixorhea y Myriopus, todos presentes en Argentina. Se designan lectotipos para Heliotropium hasslerianum (?Euploca hassleriana) y Heliotropium patagonicum y se propone la nueva combinación Heliotropium lilloi (basada en Tournefortia lilloi) para completar el cuadro taxonómico de la familia en Argentina.
10aBoraginaceae10aBoraginales10aHeliotropium10aTaxonomía10ataxonomy10aTournefortia1 aLuebert, Federico uhttps://revistas.unc.edu.ar/index.php/BSAB/article/view/1887200416nas a2200121 4500008004100000245005700041210005700098300001400155490000600169100002200175700002600197856007100223 2016 eng d00aFour new combinations in Argentinian Heliotropiaceae0 aFour new combinations in Argentinian Heliotropiaceae a192–1940 v41 aLuebert, Federico1 aFrohlich, Michael, W. uhttp://www.ojs.darwin.edu.ar/index.php/darwiniana/article/view/71700524nas a2200145 4500008004100000022002500041245010500066210006900171260000900240300000900249490000700258100002200265700002400287856006700311 2014 eng d a1988-3196, 0211-132200aTypification of Heliotropium and Tournefortia (Heliotropiaceae) species described by Ruiz and Pavón0 aTypification of Heliotropium and Tournefortia Heliotropiaceae sp c2015 ae0120 v711 aLuebert, Federico1 aHilger, Hartmut, H. uhttp://rjb.revistas.csic.es/index.php/rjb/article/view/414/40900611nas a2200145 4500008004100000245017300041210006900214300001400283490000800297100002300305700002200328700002400350700002000374856007100394 2014 eng d00aEffects of alternative sets of climatic predictors on species distribution models and associated estimates of extinction risk: A test with plants in an arid environment0 aEffects of alternative sets of climatic predictors on species di a166–1770 v2881 aPliscoff, Patricio1 aLuebert, Federico1 aHilger, Hartmut, H.1 aGuisan, Antoine uhttp://www.sciencedirect.com/science/article/pii/S0304380014002713