@article {382, title = {A Study on Pollen Morphology of Potamogeton, Zannichellia and Triglochin from China}, journal = {Acta Phytotaxonomica Sinica. Additamentum. Beijing}, volume = {28}, year = {1990}, pages = {372-378}, abstract = {

The pollen morphology of 19 species in the genera Potamogeton, Zannichellia and Triglochin from China was examined under light and scanning electron microscopes.
1. Pollen characteristics
(1) Potamogeton L. (Plate 1, 2:1-8) Pollen grains spheroidal, subspheroidal, rarely oblate or ovoid, (17-35)24.41\×27.76(18-45)\μm in size; anaperturate; exine 1-2\μm thick, 2-
layered or obscure; crass-reticulate, reticulate or finely-reticulate under LM, distinctly reticulate under SEM; muri uniform or not uniform, smooth or granular, rarely with processes; bacula thicker or thinner at the intersection of muri.
(2) Zannichellia L. (Plate 2:9) Pollen grains spheroidal, ,(20-26)23.1\×24.15(21-27) \μm in size; anaperturate; exine 1 \μm thick, stratification obscure; nearly reticulate under LM,
shallowly reticulate under SEM; luminae shallow, large and irregular, muri very thin and not uniform; bacula absent.
(3) Triglochin L. (Plate 2:10-11) Pollen grains spheroidal or subspheroidal; (20-30)23.65\×23.7(20-30) \μm in size; anaperturate; exine about 1\μm thick, stratification obscure,
finely reticulate under LM, distinctly reticulate under SEM; luminae rather large or minute; muri uniform, with 1-2 lines of granules, bacula present or absent.
2. Pollen types of Potamogeton L.
(1) Thin muri--thick bacula: Potamogeton pectinatus, P. intramongolicus, P. filiformis, P. pamiricus; (2) Uniform muri and bacula: 1) Large pollen subtype: Potamogeton
crespus; 2) Medium-sized pollen subtype: Potamogeton heterophyllus, P. perfoliatus, P. distinctus, P. malaianus; 3) Minute pollen subtype: Potamogeton oxyphyllus, P. obtusifolius, P. lucens, P. cristatus, P. gramineus, P. octandrus, P. pusillus.

}, keywords = {pollen morphology, Potamogeton, Triglochin, Zannichellia}, author = {Wang, Jing-Quan} } @article {103, title = {Non-tetrasporangiate stamens in the angiosperms: structure, systematic distribution and evolutionary aspects}, journal = {Bot. Jahrb. Syst.}, volume = {112}, number = {2}, year = {1990}, pages = {193-240}, abstract = {Derivations from the normal tetrasporangiate, dithecal pattern of angiosperm stamens are presented in a comparative study of numerous taxa and a literature survey. Regularly occuring polysporangiate stamens (with more than 4 sporangia) are known from 18 families, all dicotyledons, regularly occurring disporangiate stamens from c. 50 families. Most polysporangiate stamens have retained thecal organization with two longitudinal dehiscence lines: each of the 4 pollen sacs is simply transversally and sometimes also longitudinally subdivided into numerous sporangia. Thecal organization is lost in some Viscaceae, Polyporandra (Icacinaceae), and Mitrastemonaceae, where each sporangium individually dehisces by a pore, and in Rafflesia, where all sporangia merge into one large pore. These deviating stamen forms are often correlated with specialized pollination biology: athecal polysporangiate anthers with pollen presentation in mucilaginous masses through pores and fly pollination; dithecal disporangiate anthers with (1) also pollen presentation in mucilaginous masses through relatively small openings and often fly pollination, (2) precise secondary pollen presentation on the gynoecium, (3) cleistogamy, (4) opening with valves. In these cases efficient wide gaping of 2 mirror-symmetrical halves of each theca is not possible. The biological context and the systematic distribution strongly support the hypothesis that the cohesiveness of the basic dithecal, tetrasporangiate pattern is at least partly due to functional constraints at the time of pollen release from the mature anthers.}, keywords = {angiosperms, non-tetrasporangiate stamens}, author = {Endress, Peter K. and Stumpf, Susanne} } @book {69, title = {Aquatic plant book}, year = {1990}, note = {Juncaginaceae (incl. Lilaeaceae) - pp. 108-110}, publisher = {SPB Academic Publishing}, organization = {SPB Academic Publishing}, address = {The Hague}, keywords = {Juncaginaceae, Triglochin, Maundia, Lilaea}, author = {Cook, Christopher D.K.} } @article {71, title = {A contribution to the taxonomy of Triglochin (Juncaginaceae)}, journal = {Journal of the Adelaide Botanic Gardens}, volume = {13}, year = {1990}, pages = {43-47}, abstract = {

Triglochin ovoideum J. Black is shown to be a synonym of T. hexagonum J. Black. T. muelleri Buchen. is endemic to Western Australia, previous records of this species for South Australia being due to misdeterminations.

}, keywords = {Australia, Juncaginaceae, morphometric study, South Australia, Triglochin, Triglochin hexagonum, Triglochin Muelleri, Triglochin ovoideum}, url = {www.environment.sa.gov.au/files/15d6ed3b-0e32-40ae-b126-9f8600c1cd4a/JABG13P043_Cooke.pdf}, author = {Cooke, D. A. and Davies, R. J-P.} } @article {88, title = {Genetic variation and adaptation to flooding in plants}, journal = {Aquatic BotanyAquatic Botany}, volume = {38}, number = {1}, year = {1990}, pages = {91-108}, abstract = {Evidence exists for genetic variation that can be associated with the evolution of adaptations to flooding: variation related to flooding at the level of molecular mechanism; comparisons of the patterns of variation in flooding-tolerant and non-tolerant species; within-species variation associated with genetically-differentiated populations that enable certain higher plants to tolerate or avoid the effects of flooding are understood. Yet little is known of the genetic basis for these features and less of its variation. An analysis was done of Salicornia, which exists as locally differentiated populations in different tidal flooding regimes, from the lowest to the highest parts of salt marshes. Genetic differentiation can be demonstrated by significant selection coefficients against alien types in reciprocal transplant experiments. The genetic variation within and between these populations were investigated using restriction fragment length polymorphism studies of the ribosomal DNA (rDNA). Two rDNA repeat unit types were found, only one of which occurs in any individual plant. Only the 12-kilobase (kb) fragment was found in populations that experience the most flooding, whereas plants on the highest parts of the marsh had only the 10.5-kb fragment. Typical lower and upper marsh populations were mixed in their fragment compositions, but lower marsh areas supported a higher frequency of the 12-kb fragment than upper marsh and depressions supported a higher frequency of the 12-kb fragment than raised interfluve areas. The use of such DNA variation, which is itself unselected , as a marker for selected genetic variation shows considerable promise for the future.}, author = {Davy, A.J. and Noble, S.M. and Oliver, R.P.} }