Chara guairensis R. Bicudo 1974: 145–149

Borges, Fabio Renato & Jr, Orlando Necchi, 2017, Taxonomy and phylogeny of Chara (Charophyceae, Characeae) from Brazil with emphasis on the midwest and southeast regions, Phytotaxa 302 (2), pp. 101-121 : 109-112

Chara guairensis R. Bicudo 1974: 145–149

Fig. 16–22

Plants monoecious, up to 10 cm high, with calcium carbonate deposition. Axes 372–877 μm in diameter; internodes 0.12–0.81 times longer than the branchlets, to 0.9 cm length; cortex 3 corticate, isostichous, regular; spine-cells solitary, 43–138 μm long and 37–89 μm in diameter at the base, the basals are smaller or deciduous. Stipulodes in two whorls, two times as numerous as the branchlets; exceeding basal branchlet segment, except at basal nodes, uppers 435–932 μm long, 85–157 μm in diameter, acuminate; lowers 191–391 μm long, 59–131 μm in diameter, acuminate. Branchlets (6) 8–10 forming a whorl, 1.1–2.2 cm long; intercalary segments (3)4–8, corticate, 802–3264 μm long, 226–477 μm in diameter; basal segment ecorticate, 624–1414 μm long, 284–574 μm in diameter; 1–3 apical segments ecorticated, 802–3264 μm long, 226–477 μm in diameter. Bract-cells 4–6, forming whorls, largest ones facing the thallus, 122–843 μm long, 71–145 μm in diameter, acuminate. Bracteoles 2, 371–938 μm long, 93–184 μm in diameter, same size or larger than the madure oogonia. Gametangia sejoined, at the 1 st to 5 th nodes. Oogonia 549–1034 μm long (excluded coronula), 369–650 μm in diameter; convolutions 9–11(12); coronula 95–162 μm high, 219–266 μm wide, apex divergent. Oospores black, 558–716 μm long, 352–487 μm wide; striae of 8–11 low to prominent ridges; fossae 64–95 μm across; membrane smooth to slightly granulate. Oospore wall featureless to finely granulate in ultrastructure. Antheridia 270–535 μm in diameter, octoscutate.

Specimen examined:— BRAZIL. São Paulo: Estação Ecológica do Noroeste Paulista, Municipality of São José do Rio Preto , elev. 509 m, 20°50’31.5’’S, 49°26’17.4’’W, 4 September 2014, colls. F. R. Borges & O. Necchi Jr. ( SJRP31523 ). DNA sequences:— rbc L-KY656913 ; ITS2- KY656933 ; mat K-KY656924.

Figures

FIGURES 16–22. Chara guairensis. 16. Habit. 17. Monoecious plant with sejoined gametangia, with oogonium (red arrow) and antheridium (blue arrow) at the same branchlet. 18. Two ecorticated apical segments. 19. Basal segment of a branchlet and a oogonia. 20. Granular aspect of the osospore wall under light microscope. 21. Overview of the oospore under scanning electron microscopy (SEM). 22. Granular aspect of the oospore wall under SEM.