26 



CHARACEiE. 



[Thallogens. 



ORDER V. CHARACEjE.-Chatus. 



N G PL 1, 45. (1815) ; A. Brong. in Diet. 

 , Gen. iv. ; Schnitzl. ic.— Chareje, 



Class. 3. 474. (1823) ; 

 Eutzing, Phycologia, 



Characrje, Rich in Ilumb. et Bonpl 



Grer. El. Edin. xvii. (1824) ; Endhch. 



^Tululur symmetrically branched bodks, mnUiplkd by spiral-coated nucules, 

 filled with starch, 



Diagnosis. 



i consisting of parallel tubes, which are either 



ns of reproduction, lateral, round, succulent, brick-red globules, 

 The globules, consisting of triangular valves, enclosing jjen- 



transparent or encruated 



tubular branches. Organs 



and axillary nucules. The e ";";r' T'"^ ° nucules havillg two coats, of which the 



nil), tal tubes and slender annular tlvreaas , uiu um. e Internal firm 



external is transparent and usually surmounted by five teeth , the internal inn, 



spirally-ribbed, filled with starch granules oi various sizes 



,f which this little order is composed are among the most obscure of the 



veueUbk k -uom, in regard to the nature of their reproductive organs ; and accord- 

 vcgtuuic Kin uom, « ^ ^ the ^ under the common name of e hara> p i aced 



by Linnieus among Cryptogamous plants near Lichens ; then 

 referred by the same author to Phamoganious plants, in Monoe- 

 cia Monandria ; retained by Jussieu and De Candolle among 

 Naiads by Brown at the end of Hydrocharaceae, and by 

 Leman in Haloragere ; referred to Confervas by Von Martius, 

 Aijardh and Wallroth ; and finally admitted as a distinct order, 

 upon the proposition of Richard, by Kunth, De Candolle, 

 Adolphe Brongniart, Greville, Hooker, and others. Such being 

 the uncertainty about the place of these plants, it 

 will be useful to give a rather detailed account of 

 their structure, in which I avail myself chiefly of 

 Ad. Brongniart's remarks in the place above re- 

 ferred to, and of Agardh's observations in the Ann. 

 des Sciences, 4. 61. 



Charas are aquatic plants, found in stagnant 

 fresh or salt water ; always submersed, giving out 

 a fetid odour, and having a dull greenish colour. 

 Their stems are regularly branehed, brittle, and 

 surrounded here and there by whorls of smaller 

 branches. In Nitella the stem consists of a single 

 transparent tube With transverse partitions ; Agardh 

 remarks that it is so like the tubes of some Algals, 

 as to offer a strong proof of the affinity of the orders. 

 In Chara, properly so called, there is, in addition to 

 this tube, many other external ones, much smaller, 

 which only cease to cover the central tube towards 

 the extremities. In the axils of the uppermost 

 whorls of these branclilets the organs of reproduc- 

 tion take their origin ; they are of two kinds, one 

 called the nucule, the other the globule ; the former 

 has been supposed to be the pistil, the Latter the 

 anther. 



The nucule is described by Greville as being 

 " sessile, oval, solitary, spirally striated, having a 

 membranous covering, and the summit indistinctly 

 cleft into five segments ; the interior is filled with 

 minute sporules. Fl. Edin. xvii. This is the ge- 

 neral opinion entertained of its structure. But 

 Brongniart describes it thus : — Capsule unilocular, 

 monospermous ; pericarp composed of two enve- 

 lopes : the outer membranous, transparent, very 

 thin, terminated at the upper end by five spreading 



I \ II . -1. C'hara vulgaris ; •-' B portion of a branch with a nucule and globule ; 3. the globule more 

 i I the spiral tubes of the latter ; 5. a nucule cut open ; 6. a nucule in germination. 



