Thread–like formations in the anthers of Strelitzia reginae

Kronestedt, Eva; Bystedt, Per‐Arne

doi:10.1111/j.1756-1051.1981.tb00717.x

Cited by 13 publications

(4 citation statements)

References 3 publications

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“…Other threadlike exinal connections among pollen grains have been reported in Leguminosae (Cruden and Jensen, 1979), but these are considered to be distinct from viscin threads (Skvarla, Raven, and Praglowski, 1975). Threads of epidermal origin, and therefore very different from viscin threads in the Ericaceae, occur in anthers of Strelitzia-Strelitziaceae, Monocotyledoneae (Kronestedt and Bystedt, 1981); they serve a similar function, however.…”

Section: Discussionmentioning

confidence: 99%

Stamen development in the Ericaceae. I. Anther wall, microsporogenesis, inversion, and appendages

Hermann

Palser

2000

American J of Botany

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Development of the introrse, tetrasporangiate, and normally dorsifixed and poricidal stamens has been studied at the gross morphological and cellular level in ten species of Ericaceae. Microsporogenesis, followed in four species, is normal, with cytokinesis simultaneous, forming tetrahedral tetrads. The tricolp(or)ate pollen is shed as permanent tetrads with each segment two-celled except in Enkianthus in which pollen grains are three-celled monads. Anther-wall development is similar in all four species initially, but no regular pattern of wall development could be recognized thereafter. The tapetum, of parietal origin, is binucleate, glandular, and mainly uniseriate. Viscin threads occur with the tetrads in the three rhododendroid species. A well-developed endothecium appears only in Enkianthus.Soon after stamen initiation, anthers of nine species invert at the eventual filament-anther junction to become introrse; in Enkianthus inversion occurs close to anthesis. Microsporogenesis starts during early inversion; greater cell elongation on the abaxial side of the young anther completes inversion by the late sporogenous-tissue stage. In Erica and, to a lesser extent Calluna, inversion results from greater abaxial than adaxial increase in cell number and length just above the filament-anther junction. The single vascular strand reflects the degree of inversion. Stamens of six species are appendaged; three have only awns, two only spurs, while one has both. Appendages arise from residual meristems after inversion is completed (or almost so) in all except Enkianthus. Awns develop at what will be the apex at maturity of each anther half. Their length and orientation vary among species. Only in Vaccinium do the awns become hollow (tubules). Spurs, varying in length, shape, and size, arise on the abaxial side from the filament, connective, or thecae.

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Section: Discussionmentioning

confidence: 99%

Stamen development in the Ericaceae. I. Anther wall, microsporogenesis, inversion, and appendages

Hermann

Palser

2000

American J of Botany

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“…in Byotiia, Hesse 1981 'b). (4) Filiform cells adhering on the pollen surface of, e.g., Sfrelifzin (hlusaceae) (Kronestedt & Bystedt 1981, Hesse & Waha 1983.…”

Section: Resultsmentioning

confidence: 99%

An exine architecture model for viscin threads

Hesse

1984

Grana

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“…Pollen grains in C. coenobialis are held together by pollenconnecting threads. The occurrence of pollen-connecting threads that do not contain sporopollenin is restricted to a few genera in 12 families of angiosperms (Hesse et al 2000), including Strelitzia reginae and possibly species of Heliconia (Kronestedt and Bystedt 1981;Rose and Barthlott 1995). This study adds the Zingiberaceae to the list of families possessing pollen-connecting threads.…”

Section: Discussionmentioning

confidence: 92%

Self‐Pollination by Sliding Pollen inCaulokaempferia coenobialis(Zingiberaceae)

Wang¹,

Zhang²,

Renner

et al. 2005

International Journal of Plant Sciences

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Caulokaempferia coenobialis (Zingiberaceae) forms dense populations on steep cliffs in shady, humid monsoon forests in south China. It produces few consecutively opening bright yellow flowers that are 3 cm long and oriented parallel to the ground. Upon anther dehiscence at about 0600 hours, each pollen sac releases a drop of pollen onto the horizontally oriented style, and the two drops then merge to form an oily film that slowly flows toward the stigma, carrying out self-pollination between about 1500 and 0730 hours the next day. The distance covered by the pollen film is ca. 3 mm. There is no significant difference in fruit set between experimentally cross-and self-pollinated flowers or between naturally pollinated and bagged flowers. The low pollen/ovule ratio of 6 6 4 probably relates to the pollen grains being held together by pollen-connecting threads. The latter ensure that pollen grains always arrive as multiples, and this is the first report of such threads in the Zingiberaceae. During 35 h of observation at several locations and during three flowering periods, only three individual bees, five flies, and two butterflies visited single flowers. It remained unclear whether they affected pollination because no return visits were observed. The automatic selfing by pollen that reaches the stigma ca. 9 h after the onset of anthesis apparently constitutes a case of delayed selfing, providing reproductive reassurance in situations of low pollinator visitation.

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Thread–like formations in the anthers of Strelitzia reginae

Cited by 13 publications

References 3 publications

Stamen development in the Ericaceae. I. Anther wall, microsporogenesis, inversion, and appendages

Stamen development in the Ericaceae. I. Anther wall, microsporogenesis, inversion, and appendages

An exine architecture model for viscin threads

Self‐Pollination by Sliding Pollen inCaulokaempferia coenobialis(Zingiberaceae)

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