Chara bancroftii (J.Groves) Casanova & Karol, 2023

Casanova, Michelle T. & Karol, Kenneth G., 2023, Charophytes of Australia’s Northern Territory - I. Tribe Chareae, Australian Systematic Botany 36 (1), pp. 38-79 : 51

Chara bancroftii (J.Groves) Casanova & Karol , comb. nov., stat. nov.

Chara preissii var. bancroftii J.Groves in J. Groves & G . O . Allen, Proc. Roy. Soc. Queensland 46: 56 (1935). Type: Dalby, May 1893, T. L . Bancroft 47 (syn: BRI!, LD!); Sandgate, Nov. 1911, C. T . White 2 (syn: BM!); Enoggera Reservoir, May 1912, C. T . White s.n. (syn: BM!) .

Chara fibrosa var. fibrosa f. bancroftii R.D.Wood , Nova Hedwigia 22: 14–16 (1971), nom. inval., nom. prov.

Dioecious. Plants up to 300 mm high, sometimes lightly calcified ( Fig. 7 a ). Axes 400–500 µm in diameter; 2× corticated, isostichous, 20–28 cells around ( Fig. 7 f ). Spine cells acute and varying in length (up to 500 µm long), or globose and somewhat inconspicuous, ~50 μm in diameter. Stipulodes spreading or conical, in a single whorl, the same number as the number of branchlets in the adjacent whorl ( Fig. 7 e ). Branchlets ecorticate, 10–14 in a whorl, up to 15 mm long, segments 4–6, terminated by a cluster of bract cells ( Fig. 7 b, d ). Bract cells verticillate, up to 1 mm long, 2 or 3 of them, bracteoles 2, similar to bract cells. Bractlet present in place of an antheridium, as long or longer than the oosporangium ( Fig. 7 c ). Gametangia occurring singly or rarely geminate at the lowest 3 branchlet nodes ( Fig. 7 b, d ). Oosporangia up to 500 µm long and 320 µm wide with ~9 stripes of helical cells, coronula up to 50 µm high, cells rod-shaped ( Fig. 7 c ). Oospores very dark brown, 380–410 µm long, 200–250 µm wide. Striae of 8 or 9 flanged ridges ( Fig. 7 g ), fossa wall 40 μm across, smooth to finely granulate ( Fig. 7 h ), end cell impression ~75 μm across ( Fig. 7 i ). Antheridia up to 600 µm in diameter. Chromosomes not known.

Distribution

In freshwater wetlands in tropical and subtropical areas of Queensland and Northern Territory.

Etymology

Named in honour of Thomas Lane Bancroft (1860–1933), a medical naturalist who collected in Queensland.

Notes

Braun amalgamated all dioecious specimens that lack basal gametangia into the taxon Chara dichopitys A.Braun , nom. illeg. ( Nordstedt 1883). Groves and Allen (1935) reinstated C. preissii A.Braun and described this taxon with 1× stipulodes (unistipulate) as a variety therein , namely, C. preissii var. bancroftii . Wood and Imahori (1965) amalgamated all the taxa in section Agardhia in Australia into four species ( C. fibrosa , C. leptopitys A.Braun , C. submollusca Nordst. and C. ecklonii A.Braun ex Kütz. ), synonymising the taxon bancroftii with C. fibrosa f. fibrosa without further recognition. Wood (1971) suggested that f. Bancroftii ‘might be conveniently recognised’ as a form of C. fibrosa (‘like the normal form but with well-developed bract cells’) and provided an illustration of one of the syntypes (Bancroft 47; Wood 1971, p. 31), but no written description.

Chara bancroftii is dioecious, has a corticated axis and naked branchlets. It is distinguished from other dioecious species of Chara in Northern Territory by very large antheridia and abundant bract cells, from C. leptopitys and C. leptopitys subsp. subebracteata Nordst. by the absence of basal gametangia, and from similar dioecious species elsewhere ( C. albaniensis (R.D.Wood) Raam , C. hookeri A.Braun , C. mollusca A.Braun , and C. preissii ) by the diplostichous cortex and haplostephanous stipulodes.

Specimens examined

NORTHERN TERRITORY: 21 miles [~ 33.7 km] SE of Elliott , 20 Feb. 1969, P. K. Latz 478 (DNA, NT); 9 km E of Rabbit Flat Road House, 7 July 1980, P. K. Latz 8477 (DNA, NT); Purnie Bore, 11 Sep. 2009, A. Kerezy s.n. ( MEL, NY) . QUEENSLAND: Pretty Plains , 60 km NW of Valley of Lagoons, 9 Sep. 1976, M. Lazarides 8159 ( L, NSW); Pretty Plains Station, near Valley of Lagoons , 9 Sep. 1976, L. G. Adams 8159 ( CANB); pond on the road to Carnavon Gorge, 5 July 2010, M. T. Casanova r712 ( MEL, NY) .

Figures

Fig. 7. Chara bancroftii (a) from syntype specimen T.L.Bancroft 47 (LD); (b–i) from specimen M.T.Casanova r712. (a) Habit of whole plant, scale bar: 1 cm. (b) Female fertile whorl, scale bar: 5 mm. (c) Oogonium at branchlet node with bract cells and bractlet, scale bar: 0.5 mm. (d) Male fertile whorl, scale bar: 5 mm. (e) Base of whorl with stipulodes; scale bar: 1 mm. (f) Transverse section of the axis; scale bar: 0.5 mm. (g) Side view of oospore; scale bar: 100 µm. (h) Detail of oospore wall; scale bar: 20 µm. (i) View of oospore basal cell; scale bar: 50 µm.