form of Aloe arborescens used
to be known by the species name "mutabilis" which
means changeable or mutable. This epiphet probably
refers to the flowers which change colour as they open and to the
variability of the species. Fairly recently it has been formally
combined under Aloe arborescens to which it has affinities.
mutabilis grows naturally on vertical rock faces of Witwatersrand
National Botanical Garden at the Witpoortjie waterfall, which is
the type locality. It occurs also at Chuniespoort near Pietersburg
and westwards along the Magaliesburg to Rustenburg. This form of
Aloe arborescens is less widely distributed than the more
commonly known Aloe arborescens, but it can be found in the
hilly and mountainous area of the former southern and central Transvaal.
It is not a threatened species.
Aloe mutabilis is a beautiful aloe with a trailing stem
up to 1 metre long with offshoots. Its stem hangs downward with
the rosettes of leaves turned up at an angle. This aloe has many
leaves, 60-70cm long. The upper surfaces are glaucous green to dull
green with brownish to yellow margins. The leaf margins are armed
with harmless, yellowish orange teeth. The shape of the spaces between
the teeth is straight, not rounded as with the commonly known Aloe
inflorescence of this aloe is simple, up to 90cm high, but sometimes
with 1 to 2 branches. It has a bicoloured raceme. Individual flower
buds are red buds and then on opening the flowers turn yellow or
greenish yellow. The flowers of some forms are uniformly red. Flowering
time is winter, from May to July, depending on the regional climate.
Aloes in the Northern Province may flower at a different time to
those at Witpoortjie waterfall.
The commonly known pollinating agents are nectar feeding birds,
bees and wind.
Growing Aloe mutabilis
Aloe mutabilis is easily cultivated from seeds and offshoots.
The offshoots can be planted straight into river sand. Its bicoloured
racemes make it a popular garden plant in highveld gardens. Aloe
mutabilis grows fairly fast and it can withstand fairly severe
frost. It makes a magnificent rockery specimen when grown at the
highest point of the rockery with the rosette hanging downward.
Thompson T. Mutshinyalo
Walter Sisulu National Botanical Garden