Chara behriana (A.Braun) F.Muell. ex 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 : 51-54

Chara behriana (A.Braun) F.Muell. ex Casanova & Karol , comb. nov., stat. nov.

Chara contraria var. behriana A.Braun ex F.Muell., Linnaea 25: 709 (1853). Type: In fontis vallis subsalsis Salts Gully prope Bethanien, South Australia, 1848, F. von Mueller s.n. [possibly with H. H.Behr] (holo: MEL!) .

‘ Chara behriana’: F.Muell. herb., ined.

[ Chara vulgaris var. gymnophylla auct. non ( A.Braun) Nyman: R.D.Wood, Nova Hedwigia 22: 14–16 (1971).]

Monoecious. Plants up to 120 mm high, usually with thick calcium carbonate deposition on the thallus. Axes 600–700 µm in diameter; unevenly 3× corticated ( Fig. 8 f ), secondary and tertiary cells smaller than primary cells, somewhat isostichous to tylacanthous, 26–30 cells around ( Fig. 8 d ). Spine cells globose and somewhat inconspicuous, ~50 μm in diameter ( Fig. 8 b ). Stipulodes somewhat obscure, in 2 whorls, each whorl up to 2× the number of branchlets, upper whorl ~100 μm long, lower whorl ~50–80 μm long ( Fig. 8 e ). Branchlets 9 or 10 in a whorl, up to 12 mm long, segments 5 or 6, terminated by a blunt cell, scarcely corticated, a few cortical filaments on the first branchlet cell, and with cortical initials at the branchlet nodes ( Fig. 8 a ). Bract cells highly reduced abaxially, longer, usually 2 adaxially (to 1000 μm long) at the branchlet nodes, bracteoles 2, ~800 μm long ( Fig. 8 c ). Gametangia conjoined singly at the lowest 2 or 3 branchlet nodes ( Fig. 8 c ). Oosporangia up to 1000 µm long and 400 µm wide with 12 stipes of helical cells, coronula up to 150 µm high, cells peg-shaped, spreading. Oospores brown to black, 530–680 µm long, 350–370 µm wide ( Fig. 8 g ), often with a calcified covering (gyrogonite 700–720 µm long). Striae of 11 or 12 low ridges, fossa wall 60–70 μm across, finely granulate ( Fig. 8 h ), basal cell impression ~80 µm across. Antheridia up to 200 µm in diameter. Chromosomes not known.

Distribution

South Australia, the Victorian Mallee, and into the central part of the Northern Territory.

Etymology

Named in honour of Hans Hermann Behr (1818–1904), German-born botanist who collected in Australia in the 1840s.

Notes

Wood (1962) synonymised C. contraria and all its varieties and forms under C. vulgaris . He followed this treatment for Australian species in this group ( Wood 1971) and placed C. contraria var. behriana in synonymy with C. vulgaris var. gymnophylla . Investigation of European material of C. vulgaris indicates that it has well-developed bract cells and brown oospores, which differs from Australian material. European C. contraria also differs significantly (two times corticated axis, evenly corticated branchlets, smaller oospores), so von Mueller’s manuscript name Chara behriana (≡ C. contraria var. behriana A.Braun ) is here adopted for this species.

Chara behriana has a corticated axis, and largely naked branchlets. It is distinguished from other species with two rows of stipulodes by the scant cortication on the branchlets, black oospores and the occurrence of gametangia on uncorticated nodes, and from species with ecorticate branchlets in subgenus Charopsis by the presence of gyrogonites on the oospores, and by the unilateral development of the bract cells. It differs from C. conimbrigensis A. G. Cunha in having less conspicuous and poorly developed stipulodes and consistently singular conjoined gametangia.

Specimens examined

NORTHERN TERRITORY: Harts Camp Waterhole on the Finke River, Henbury Station. In clear water on sandy bottom, 26 May 2012, R. Breen v053 ( MEL); Lake Nash , 23 Oct. 1976, A. S. Mitchell (DNA); Illara Waterhole , 10 km NW of Tempe Downs Station Homestead, 28 Nov. 2001, P. K. Latz 18381 (DNA, NSW, NT); Pioneer Creek , 6 km E of Glen Helen Resort, 17 Oct. 2003, P. K. Latz 19532 (DNA, NT) .

Figures

Fig. 8. Chara behriana, from R.Breen v053 (MEL). (a) Fertile branchlet whorl, scale bar: 5 cm. (b) Base of branchlet whorl and axis of shoot, scale bar: 1 mm. (c) Two fertile branchlet nodes, scale bar: 1 mm. (d) Transverse section of axis cortication, scale bar: 0.5 mm. (e) Base of branchlet whorl with the stipulodes,scale bar:0.5 mm. (f) Longitudinal view of axis cortication and spine cells, scale bar: 1 mm. (g) Oospore, scale bar: 200 µm.(h) Detail of oospore wall,scale bar:20 µm. (i) Impression of basal cell on the oospore,scale bar:100 µm.