J Syst Evol ›› 2005, Vol. 43 ›› Issue (3): 225-232.

• Research Articles • Previous Articles     Next Articles

Morphological observations on metamorphosed sepals in Anemone rivularis var. flore-minore (Ranunculaceae)

1CHANG Hong‐Li, 2REN Yi*, 3FENG Lu‐Tian   

  1. 1(College of Life Sciences, Northwest University, Xi’an 710069, China)

    2(College of Life Sciences, Shaanxi Normal University, Xi’an 710062, China)

    3(Shaanxi Institute for Drug Control, Xi’an 710061, China)renyi@snnu.edu.cn
  • Published:2005-05-18

Abstract: Sepals of the normal and metamorphosed flowers in Anemone rivularis var. flore-minore were comparatively studied by using the methods of macroscopical morphology and microscopical observation for having a better understanding of the processes of floral metamorphosis in this taxon. The normal flowers had 5(-8) white, obovate and entire sepals up to 1.3×0.5 cm. The sepals had the opening dichotomous venation, and were very sparsely hairy in the distal region on the lower surface. No stomata were observed on the upper surface but a few were observed on the lower surface. The metamorphosed flowers had sepals up to 20 in number. The sepals showed the morphology of bracts or foliage leaves, and had the reticulate venation, and were green, obovate or elliptic, up to 5×3 cm, densely hairy on both surfaces, margin entire or 3-lobed, and each lobe was lobulate and margin serrate. Stomata were observed on both surfaces, and the number of stomata increased towards the increasing floral metamorphosis. A continuous gradient from normal sepals to metamorphosed ones was observed with respect to the number, size, colour, shape, division, distribution of stomata, hairiness and venation. The leaf-like features exhibited by the metamorphosed sepals indicate that such sepals should be produced through atavism and that they should be of the same origin as the bracts.

Key words: Anemone rivularis var. flore-minore, sepal, metamorphosis, homoeosis.