Fossil pollen dating

Sporophyte woody; stem branching lateral, meristems axillary; lateral root origin from the pericycle; cork cambium [producing cork abaxially], vascular cambium bifacial [producing phloem abaxially and xylem adaxially].Growth of plant bipolar [roots with positive geotropic response]; plants heterosporous; megasporangium surrounded by cupule [i.e.Abscisic acid, L- and D-methionine distinguished metabolically; pro- and metaphase spindles acentric; class 1 KNOX genes expressed in sporangium alone; sporangium wall 4≤ cells across [≡ eusporangium], tapetum , secreting sporopollenin, which obscures outer white-line centred lamellae, columella , developing from endothecial cells; stomata , on sporangium, anomocytic, cell lineage that produces them with symmetric divisions [perigenous]; underlying similarities in the development of conducting tissue and of rhizoids/root hairs; spores trilete; shoot meristem patterning gene families expressed; MIKC, MI genes, post-transcriptional editing of chloroplast genes; gain of three group II mitochondrial introns, mitochondrial trn S(gcu) and trn N(guu) genes 0.[Anthocerophyta Polysporangiophyta]: gametophyte leafless; archegonia embedded/sunken [only neck protruding]; sporophyte long-lived, chlorophyllous; cell walls with xylans.Pirani & Prado Gametophyte dominant, independent, multicellular, initially ±globular, not motile, branched; showing gravitropism; acquisition of phenylalanine lysase* [PAL], flavonoid synthesis*, microbial terpene synthase-like genes , triterpenoids produced by CYP716 enzymes, CYP73 and phenylpropanoid metabolism [development of phenolic network], xyloglucans in primary cell wall, side chains charged; plant poikilohydrous [protoplasm dessication tolerant], ectohydrous [free water outside plant physiologically important]; thalloid, leafy, with single-celled apical meristem, tissues little differentiated, rhizoids , unicellular; chloroplasts several per cell, pyrenoids 0; glycolate metabolism in leaf peroxisomes [glyoxysomes]; centrioles/centrosomes in vegetative cells 0, microtubules with γ-tubulin along their lengths [?

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Buxaceae, etc.]; (vessel elements with simple perforation plates in primary xylem); nodes 3:3; stomata anomocytic; flowers (dimerous), cyclic; protandry common; K/outer P members with three traces, ("C" , with a single trace); A ? anatomy; leaf waxes hummocky; leaves opposite, scale-like; flowers single, terminal; P uniseriate, 4; anthers extrorse, completely connate and surrounding G except for small apical pore, polythecate; pollen 2-porate [? The majority of the family is likely to have ericoid mycorrhizae (see below), although other mycorrhizal types are known here, and his association with fungi is likely to be an important element in the ecological success of the family. Kron and Luteyn (2005) discuss the historical biogeography of Ericaceae; an Eurasian origin of the family is likely.Sporophyte long lived, cells polyplastidic, photosynthetic red light response, stomata open in response to blue light; plant homoiohydrous [water content of protoplasm relatively stable]; control of leaf hydration passive; plant endohydrous [physiologically important free water inside plant]; PIN[auxin efflux facilitators]-mediated polar auxin transport; (condensed or nonhydrolyzable tannins/proanthocyanidins ); xyloglucans with side chains uncharged [?level], in secondary walls of vascular and mechanical tissue; lignins ; roots , root hairs and root cap ; stem apex multicellular [several apical initials, no tunica], with cytohistochemical zonation, plasmodesmata formation based on cell lineage; vascular development acropetal, tracheids , in both protoxylem and metaxylem, G- and S-types; sieve cells [nucleus degenerating]; endodermis ; stomata numerous, involved in gas exchange; leaves , vascularized, spirally arranged, blades with mean venation density ca 1.8 mm/mm], all epidermal cells with chloroplasts; sporangia adaxial, columella 0; tapetum glandular; ?For example, if reticulate-perforate pollen is optimized to the next node on the tree (see Friis et al.2009 for a discussion), it effectively makes the pollen morphology of the common ancestor of all angiosperms ambiguous...

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