The dimorphic pollen occurs in 2 spatially and morphologically distinct staminal whorls with one type, the lower antepetalous whorl opposite the petals, functioning as food for visiting insects, and the other, higher antesepalous
whorl, for fertilization (Muller 1981; Kim et al.
Female flowers in date palm (Phoenix dactylifera L.) possess tricarpellary apocarpous pistil consisting of three independent carpels, while rudimentary androecium is represented by two whorls of three staminodes each alternately arranged in antepetalous and antesepalous
position (DeMason et al., 1982).
Each flower is characterized by an actinomorphic, pentamerous perianth composed of a whorl of sepals and a whorl of petals, a haplostemonous androecium with antesepalous
stamens, and a bicarpellate gynoecium; the styles of the flowers are fused to free, and the single stigma is capitate.
Pollen from the typically more numerous antepetalous anthers is on average larger, thicker-walled with more distinct pseudocolpi and exine sculpture, and with a more perforated tectum than pollen from the antesepalous
anthers (Muller, 1981b; Kim et al., 1994: Fujiki et al., 2001).
40 mm long, slightly complanate, white, the antepetalous ones adnate to the petals for 18-20 mm, the antesepalous
ones adnate to the petals for 10-11 mm; anthers linear, 9-11 mm long, dorsifixed ca.
Stamens included; filaments complanate, lilac toward the apex, the antepetalous ones adnate to the petals for 6-8 mm, the antesepalous
ones free; anther base obtuse-sagittate, apex apiculate, apiculus nigrescent, dorsifixed above the base at 1/3 of its length; pollen globose, diporate, exine psillate; stigma conduplicate-spiral, ellipsoid-capitate, lilac-purple, margins crenulate-lacerate; ovary obconic, trigonous, 8-9 mm long, 6-7 mm in diameter at the apex, white, glabrous, bearing inconspicuous longitudinal sulcus; placentation apical; ovules shortly caudate; epigynous tube inconspicuous, ca.
They occur in Hamamelidae as a whorl alternating with antesepalous
stamens, suggesting their homology with petals and as "a transitional stage between apetalous and petalous flowers" (Grepet & Nixon, 1996: 37).
15 x 3-3.5 mm, free, erect at anthesis or nearly so, green except for the paler green apical margins, bearing 2 densely and prevailing downwardly-oriented, fimbriate-lacerate appendages 3-4 mm above the base, as well as 2 conspicuous longitudinal callosities nearly equaling the anthers; filaments terete, greenish-white, the antepetalous ones 7-8 mm long, adnate to the petals for 4-5 mm, the antesepalous
6 mm, the antesepalous
ones 11-12 mm long, free; anthers 1.7- 2 mm long, base and apex obtuse, compressed laterally, green, dorsifixed at middle; pollen sulcate, ellipsoid, exine reticulate, muri narrowed; stigma conduplicate, ca.
4 mm, lobes narrowly elliptic to obovate- lanceolate, obtusely carinate, apex acute and apiculate, glabrous, whitish-green; petals 36- 38 mm long, connate at the base for 7-10 mm, lobes sublinear, erect, 29-39 x 6 mm, green toward the apex except for the white apical margins, bearing 2 long fimbriate appendages at the tube apex, as well as 2 conspicuous longitudinal callosities slightly shorter than the filaments, apex obtuse-cucculate, corolla tubular; filaments the antepetalous ones adnate to the petals for 20-27 mm, the antesepalous
ones adnate to the petals tube and free above it; anthers ca.
7 mm above the base with fimbriate-lacerate apex; filaments whitish, partially concealed by callosities, 12-13 mm long, subterete, the antepetalous ones adnate to petal for 7-8 mm, the antesepalous
ones free; anthers sublinear, base obtuse, apex acute and apiculate, dorsifixed slightly below the middle, 6.5-7 mm long; pollen broadly ellipsoidal, biporate, pores small, exine psillate or nearly so; style cylindrical, whitish, ca.
45 mm long, terete, white, the antepetalous ones adnate to the petals for 32 mm, the antesepalous
ones adnate to the petals for ca.