Stamen appendage

Species of the mulberry family may be either monoecious or dioecious, depending on whether male and female flowers occur on the same plant (monoecious) or on separate plants (dioecious). Flowers of the Moraceae are in tightly packed groups, known as heads, spikes, catkins, or umbels. Fig flowers are produced inside a synconium, a hollow fleshy structure. The small flowers lack petals. Male flowers consist of four sepals, which are usually leaf-like appendages, and four stamens. Female flowers consist of four sepals and a pistil with a two-chambered ovary. 

A complete stamen (Fig. 93Z ) consists of a more or less slender stalk portion called a filament and a terminal appendage called the anther or microsortis. The anther is generally vertically halved by an upgrowth of th e filament, called the dividing the anther... 

Stamens with appendages in the outermost androecial whorl are only present in a few genera of extant Lauraceae Rhodostemonodaphne p.p., Urbanodendron, Phyllostemodaphne, Brassiodendron, Endiandra, Cryptocarya Hyland, 1989 Rohwer, 1993), some Hernandiaceae (Kubitzki, 1970a, b, 1993b), Atherospermataceae (Philipson, 1993), and a fewMonimiaceae Hortonia, Peumus, Monimia] Philipson, 1993). 

Taxon Number of fertile stamen Staminode whorls whorl Staminal appendages Number of sporangia Reference... 

Fig 8.2 Peganum harmala. Floral bud, transverse section series. Sepal basal lateral appendages marked with asterisks [ ]. (A) Distal zone, live sepals and five petals with contort aestivation. (B) Fifteen stamens surrounding three carpel tips [c], free but postgenitally united. 

Fig 9.5 Flower morphology of Heterocentron elegans (A)-(B), Clidemia octona (C)-(F) and of Dissotis rotundifolia (G)-(ff). (A) Mature flower bud with four petals (removed) and eight stamens. (B) Detail of flower showing a style surrounded by an extension of the ovary wall at the base. The anthers are provided with basal auriculate appendages. (C) Development of sepal lobes surrounding petal primordia. (D) Initiation of stamens and carpels. Note the... 

It is demonstrated that the corona represents a complex structure, which is part corolla and part androecium, represented by two series of distinct staminodes. The argument that the flower is apetalous because of the strong resemblance and association of outer petaloid appendages to the stamen tube gains little support because of the initiation of petal lobes before the androecium and from the fact that petals and stamens are connected by a common stamen-petal tube, which is widespread in asterids. A floral developmental study of genera of Scytopetaloideae, Crateranthus and Astemnthos is expected to confirm the earlier initiation of the outer corolla before the centrifugal development of the androecium. 

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