Fig. 4

Developing inflorescence of E. pusilla. a Apical view of a young developing inflorescence. A central meristem is present and below it two flowers are visible, each subtended by a bract. The distal flower (F1) is primordial and the next flower (F2) is somewhat more developed. b Apical view of a developing flower in an early developmental stage. The scars of the three removed sepals are visible, two are adaxially (lateral sepals) and one is abaxially (median sepal) situated. More central in the flower, two abaxial-lateral petals and one adaxial developing petal (lip) are present. Most central in the flower is the primordium of the gynostemium. c–d Developing adaxial petal (lip) with callus (boxed). e–h Successive stages of the development of the gynostemium with the developing fertile stamen central and stelidia laterally. In (e), the scar of the removed abaxial sepal is visible. Below the fertile stamen, the scar of the adaxial petal (lip) can be seen. In between the fertile stamen and the adaxial petal (lip), the stigmatic cavity is present. In (f and g), the two adaxial (lateral) carpels are visible (arrowed). In (h), the abaxial carpel is incorporated in the stigmatic cavity. i Apical view of an inflorescence axis with a removed developing flower. In the upper half of the micrograph, the apex of the axis is visible as well as a flower at very early developmental stage, subtended by a bract. In the lower half, in the scar of the removed developing flower, six vascular bundles are visible (arrowed). Abbreviations: Red asterisk = apical meristem; B = bract; F = flower (primordium); c = carpel; gm = gynostemium; pe = petal; se = sepal; s = fertile stamen; s(sl) = stelidium. Color codes: dark green = bract; red = petals; orange = gynostemium; yellow = androecium