Organographie der Pflanzen, insbesondere der Archegoniaten und Samenpflanzen.

Chiral events in developing gametophores of Physcomitrella patens and other moss species are driven by an unknown, universal direction‐sensing mechanism

“…Our study demonstrates the usefulness of gametophore chirality to resolve some questions related to moss development. Altogether, our results confirm findings reported in the majority of classic literature showing a clockwise division of AC (Ruhland, ; Goebel, ; Crum, ; Goffinet et al., ), while also presenting evidence for a counterclockwise division. The latter confirms further our interpretation of AC activity depicted in a published photograph of a Physcomitrella tip (Harrison et al., ).…”

“…Further, three‐dimensional gametophore growth proceeds through the divisions of a tetrahedral apical cell (AC), paralleling its three lateral faces (Schumaker and Dietrich, ; Goffinet et al., ; Harrison et al., ). While the apical growth and architecture of bryophyte gametophytes have long been studied using classical plant anatomy and morphology approaches (Ruhland, ; Goebel, ; Hébant et al., ; Coudert et al., ; Glime, ), the introduction and genetic definition of the model plant Physcomitrella patens can now allow new insights through experimental biology (Schumaker and Dietrich, ; Crum, ; Cuming, ; Harrison et al., ; Knight and Perroud, ; Perroud et al., ; Yasumura et al., ; Coudert et al., ; Demko et al., ). Despite this advancement, we still know surprisingly little about gametophore circumferential symmetry and chiral aspects of moss development, i.e., whether its structures or developmental processes occur in two alternate configurations, one being a mirror image of the other.…”

“…This configuration of leaves assembled in three rows, typical for Tristichium , Tetraphis , or Fontinalis gametophores (Crum, ), is known as tristichous phyllotaxis, uncommon in higher plants even though exceptions do occur in Cyperaceae and Podostemaceae (Rutishauser, ; Imaichi et al., ). In mosses, 3CLs often deviate from the vertical course, leading to spirotristichous phyllotaxis often described by means of the Fibonacci numbers (Ruhland, ; Goebel, ), sometimes not correctly (Crum, ; fig. 13h).…”

“…However, we do not know the direction of inclination taken by 3CLs in these cases. Circumferential displacement of every fourth leaf relative to the position of the first leaf results from AC division planes being non‐parallel to the cell sides (Goebel, ). Theoretically, these new oblique cell walls may orient to the left (S) or right (Z), and this orientation must be maintained in consecutive divisions to cause CL deviation (Fig.…”

Embryogenesis ofAtriplex halimusL. (Amaranthaceae)

“…Hall and Clements (1923) describe embryos with vertical radicle, directed towards the style within the sub-genus Obione (Atriplex dioica and Atriplex monolifera), whereas the Euatriplex subgenus possesses a horizontal radicle. Goebel (1933) shows that the Atriplex hortensis ovules are amphitropous, with their funicle merged with the ovule, as observed for anatropous ovules, but the embryo is curved as in campylotropous ovule.…”