Page 197 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

SUBSTRATE PLANTS 195

Rotala macrandra Crinum thaianum
Giant Red Rotala Onion Plant

ORIGINS Asia, occurring in India and on the nearby ORIGINS Southeast Asia; particularly abundant
island of Sri Lanka. in southern Thailand.
SIZE Typically about 8 in (20 cm) tall in aquariums. SIZE Leaves can be up to 60 in (1.5 m) long.
WATER Temperature 72–79°F (22–26°C); soft WATER Temperature 64–81°F (18–27°C); hard
(50–100 mg/l) and acidic (pH 6.5–6.9). (100–150 mg/l) and around neutral (pH 6.5–7.5).
PROPAGATION Split off shoots and plant these in the PROPAGATION May occasionally develop offsets on the
substrate, where they will root easily. bulb; these can be taken off and replanted.
Bright lighting accentuates the red coloration of Numerous types of Onion Plant are available, all
this attractive species. Unfortunately, Giant Red of which reach a relatively large size. The straplike
Rotala is difficult to establish in aquariums, and it can leaves can be up to 3 in (7.5 cm) wide and are
be damaged easily by rough handling. However, it variable shades of green. In the wild, the Onion
is worth the effort, because it makes a striking Plant will often grow above the surface, and it
contrast with green plants. To create the best is then that it produces its characteristic white
effect, plant shoots flower. The flower reveals that this is not a
in groups. member of the onion family but a relative of the
popular Amaryllis houseplant. The Onion Plant
looks best in a large, deep aquarium, especially
when planted toward the back of the tank. If
the bulb is set deep in the substrate, with just
its shoulder visible, it should soon establish itself
and start sprouting leaves. Onion Plants are quite
tough, so they can be incorporated successfully in
aquariums housing large vegetarian fish, where more
delicate plants would be consumed. They are also
Side shoots Leaves are
can be broken greenish above unfussy about their water conditions and do not
off and rooted and reddish below require brightly lit surroundings.
Nymphaea maculata
African Tiger Lotus

ORIGINS Found naturally in parts of western Africa,
notably in Gabon and Congo.
SIZE Spread may be up to 18 in (45 cm) across.
WATER Temperature 68–86°F (20–30°C); soft
(50–100 mg/l) and around neutral (pH 6.5–7.5).
PROPAGATION It may be possible to take shoots off
the tuber. Can also be grown from seed.
The Tiger Lotus, a broad-leaved relative
of the water lily, has two distinct forms.
The African Tiger Lotus, shown here, has
greenish leaves with purple blotches
and pale green undersides. The
Red Tiger Lotus has reddish
leaves, again marked with
purple. Once planted in the
substrate, tubers should grow
rapidly under bright light.
The leaves, up to 6 in (15 cm)
in diameter, provide retreats
for small fish. Tiger Lotuses
may flower in the tank,
producing white blooms above
the surface that open at night.
If the resulting seeds are left
to fall into the tank, they
may germinate on the substrate.

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