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? ^96 15. Zygnema. 1. HYDROPHYTiE. Pl.cell.apk.
F. CoNJUGATiDE^. TfialUis cylindrical, threadlike,
K tubular, jointed ; coupling laterally, either by pushing out
X a transverse tube from the middle of the joint, or by uniting
^ at the angles ; i,pore one in each joint.—Fresh-water, green,
1 XV. 15. ZYGNEMA. Agardh. Zygneme.
Thallus threadlike, simple, tubular ; jointed ; coupling
r; parallelly by a short traverse tube emitted from the middle
- ^f each joint, thi-ough which the granules in the joints of
- one plant pass into the opposite joint of the other plant,
r and there form a single spherical spore; granules form-
i; ing spots in each joint.
1 . Zygnema peclinatum. ComlUke zygneme.
Threads shining, rather longer than broad ; spots two,
®r oblong or 3-toothed in each joint.
Conjugafa pectinata, Vattc/ier, 77.
Zygnema peciina(uin, Agardh Syn. 102.
Conferva pectinata, De Candolle Fl. Fr. 2, 56; Engl. Bot. 1610.
On stones, or floating in running waters.
Tiijts light green, growing blackish ; sporcB spherical,
^ lodged in the transverse tube, according to Agardh.
(3. con/luens. Joints as long as broad ; spots dense and
K nearly confluent.
Conferva bipuiictata, Dllhv. 2.
.' 2. Zygnema hipunclatmn. Two-dotted zygneme.
Threads shining, twice as long as broad ; spots 2, stellate.
Conferva bipunctata. Roth Cat. 2, 204; not of Engl. Bot.
Conferva Stcllina, Mutfer in N. Act. Petr. 3, 93.
Conferva cruciata, De Candolle. Ft. Fr. 2, 56.
** Conjugala stellina. Voucher, 75.
' - Coiijngata cruciata, Faucher, 76.
-.' Zygnema cruciaitim, Agardh Syn. 102.
Ditches and stagnant waters.
Ttifts entangled, floating ; spots starlike, radiated or
IS. angular.
^. gracile. Joints three times as long as broad ; spots 2,
tc roundish.
Cunjugata gracilis, Vauchcr, 73.
Conferva gracilis, De Cando'le Fl. Fr, 2, 55.
Zygnema gracilis? Agardh Syn. 103.
y. unipundatitTn. Joints as long as broad ; spot 1,
R roundish.