Environmental Engineering Reference
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B
A
20 μm
50 μm
30 μm
300 μm
(a)
(b)
Figure 4.4
(a)
Batrachospermum.
Top: Detail showing a whorl of uniaxial tufts (A) arising from the main axis (B).
Bottom: General view of thallus (b)
Audouinella
. Details from an attached colony showing clear red coloration. Top:
Cluster of ovoid asexual monospores at the tip of a short lateral branch. Bottom: Simple branched filaments composed
of cylindrical cells. Reproduced with permission from R. Matthews.
up to 20 cm in length and show little to
frequent branching. When growing in water
plants look like stiff tufts of black or brown
hair, each hair having irregular thickenings
along its length. Chloroplasts are numer-
ous, parietal and disc-shaped. Widespread in
moderate- to fast-flowing streams attached to
stones. Rhodophyta. Plate II.
Thalli are crustose, reddish in colour and
closely adhere to the substrate. Cells cubi-
cal, in vertical rows, each cell up to 16 μmin
diameter. Rhodophyta. Plate II.
(b) Filaments attached to a surface, radiating
from a central point forming a flattened disc
or slightly rounded cushion of cells - some
of which have fine hairs or setae which are
sheathed at the base . . . .......
Coleochaete
12
(10) (a) Cells of filaments stacked in verti-
cal rows to form a pseudoparenchymatous
mass. These filaments are found as a thin,
flat rose-coloured encrustation on stones.
..........................
Hildenbrandia
Coleochaete
is uniseriate when younger,
subsequently growing as a mass where fil-
aments tend to merge to form a pseudo-
parenchymatous mass. Branches may be
dichotomous or irregular. There may be an
erectpartofthethallusaswellasthelattened
Thalli of
Hildenbrandia
grow over stones in
rivers and streams, frequently in hard waters.
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