Aloes and Lilies of Ethiopia and Eritrea

46 ALOACEAE
Key to the species
their quest for rarities. All species of Aloe (except A.
vera) are in the CITES (Convention on International
Trade on Endangered Species) list, clearly indicating
their vulnerability.
Aloes are keystone species in the ecosystem, being
perennial plants, able to tolerate extreme environmental
conditions and provide important source of shelter,
nectar food and moisture, especially for birds. It is thus
imperative to document information on the biology,
ecology, distribution and chemistry of these species
in order to take appropriate measures to conserve and
promote sustainable use of these botanical treasures.
Due to the size and succulence of these plants, herbarium
material of this group is often poorly prepared. It is
however, possible to collect herbarium specimens
in a non­destructive manner by removing only the
inflorescence and a few representative leaves. It is vital
to have information on the overall size and habit of the
plant and to take precautions to ensure that herbarium
material dries reasonably quickly. Leaves should be split
length­wise, keeping the upper surface and margin intact
if possible, and all the central water storage tissue scraped
away (V­shaped leaves also need to be split along the
middle), after which drying is easier. If this is not done,
leaves can take weeks, even months, to dry, and often rot
or discolour badly. Flowers are best preserved by dipping
in petrol or boiling water, or they may be placed in a deep
freezer. If this is not done most flowers will drop off and
there is excessive shrinkage and distortion. Good photos
are important supplements to herbarium material.
Some of the species are closely related and might be difficult to differentiate
from each other in herbaria collections. All measurements in the keys are
based on dried material and are thus often smaller than those for fresh
material. Shrinkage of the very fleshy flowers is significant, usually about
20(25)% in well pressed flowers. Marginal teeth of the leaves are counted
towards the leaf base.
1. Perianth and bracts shortly hairy or papillate; racemes commonly over 40 cm
long, erect, inflorescence unbranched or with up to 4 lateral racemes 2
- Perianth and bracts glabrous; Racemes up to 35 cm long, usually less,
inflorescence often profusely branched, rarely with fewer than 4 racemes 7