Members of the family Boraginaceae are herbs, shrubs or trees,
characterized by leaves with rough hairs, inflorescences sometimes
coiled at their tips, and fruit a capsule or drupe (fleshy) of four
Boraginaceae is a family displaying a range of differences in habit,
leaf, inflorescence, flower and fruit morphology.
The species are mainly herbs (see Anchusa
capensis), but shrubs or trees, usually multi-stemmed, also
occur (see Ehretia rigida
and Cordia caffra
). Their life cycles may be annual, multiseasonal or perennial.
The stems of the herbaceous species are erect, procumbent (lying
on the ground without rooting at the nodes) or decumbent (spreading
horizontally at first but then growing upwards).
The plants are variously hairy. Setae (stiff hairs) with 1- or
2- or 3-layered, multicellular bases, unbranched or branched hairs
and unbranched multicellular glandular hairs occur. The leaves are
simple, with or without a leaf stalk. The inflorescences are often
coiled at the apex, uncoiling as the flowers open. The corolla is
sympetalous (having petals which are partly fused); the throat may
be naked, hairy, with pouch-like swellings (gibbosities) or has
fornices (small scales) present. The colour of the corolla varies
from white, yellow, shades of blue and purple to brownish red or
pink. The stamens are exserted or included, borne on the corolla.
Pollen grains of different
types are produced in the anthers. The fruit is a capsule or
drupe of four 1-seeded nutlets, the nutlets are glabrous or variously
The family Boraginaceae comprises about 135 genera and 2 600 species,
distributed throughout the tropical, subtropical, and temperate
regions of the world. A broad family concept is followed here, regarding
the families Hydrophyllaceae and Lennoaceae as synonyms of Boraginaceae.
Members occur on all the continents and also on many islands such
as the Cape Verde Islands and Madagascar. Although Boraginaceae
is only a medium-sized family (21 genera and 110 species) in the
Flora of southern Africa (FSA) compared to the largest family Asteraceae
(246 genera and 2 240 species), the members are widespread over
the area.The members of Boraginaceae occur in the Desert, Forest,
Fynbos, Grassland, Nama-Karoo, Savanna, Succulent Karoo and Thicket
Biomes of the FSA region. They are therefore found in a variety
of habitats, often inhabiting disturbed places like road verges
and are thus easily collected and recorded.
Different types of plant distribution patterns are found among
members of the family Boraginaceae in southern Africa. Cordia,
the largest genus in the family with an estimated 350 species is
pantropical with about eight species occurring in southern Africa.
Besides Lobostemon and Echiostachys, which is more
or less endemic in the Western Cape (winter rainfall), all other
genera occur either elsewhere in Africa or in the world. The genera
Anchusa, Cynoglossum, Lappula, Lithospermum and Myosotis
have indigenous members described from southern Africa with their
nearest relatives in Europe and Asia.
Name and History
In 1789 Antoine Laurent de Jussieu published a plant classification
system, Genera plantarum, with a description of 'Borragineae' as
one of 100 orders (i.e. families). Many of his families are still
maintained in modern classifications. De Jussieu based 'Borragineae'
on the genus Borago L. When Linnaeus established the genus Borago, he used the Latin name burra, meaning a hairy garment,
in allusion to its hairy leaves.
Members of Boraginaceae in southern Africa occur mainly in summer
rainfall regions where grassland and savanna prevail. They are subject
not only to winter drought and frost, but also to natural and man-made
veld fires. These species are adapted to survive unfavourable conditions
by means of sturdy, often very old, fire-resistant rootstocks and
mass seed production after fire-stimulated flowering, for example
Trichodesma angustifolium. The plants resprout and flower
shortly after burning, usually well before the onset of the rainy
season. Observations of the effect of fire on Trichodesma physaloides
(chocolate bells)[see above] in the Pretoria National Botanical
Garden, National Botanical Institute, South Africa, showed that
unburned plants of the species did not flower at all or produced
only a few inflorescences, as opposed to burned plants of the species
in the same grassland that sprouted and produced inflorescences
in profusion after a natural fire. It seems that a change in temperature
also induces flowering of plants-Ehretia rigida subsp. nervifolia,
a multistemmed shrub, flowers abundantly for a very short time even
before the rains start.
An important feature in the southern African flora is the presence
of members of genera that are naturalized aliens. Two species of
Echium were introduced into southern Africa, possibly as
part of stock feed or birdseed. They have become troublesome invaders
and are now declared weeds.
An often neglected aspect of species is their adaptations for dispersal.
The fruits and seeds of members of the family Boraginaceae in the
southern African flora are dispersed in various ways. The bright
orange-red drupes of Ehretia and Cordia are dispersed
by birds or mammals such as monkeys, members of these genera are
often found in bush clumps and along fences. Ants carrying the nutlets
of Heliotropium amplexicaule into their nests were observed
in the Pretoria National Botanical Garden where this species is
a most successful invader of sandy, disturbed areas. Seeds of the
genera Codon and Wellstedia are dispersed by the opening
actions of their capsules, whereas nutlets of the genera Cynoglossum,
Lappula, Rochelia and some members of Trichodesma and
Afrotysonia are characterized by the presence of barbed hooks
(glochidia) that are attachment devices that enable seeds to hook
on to passersby to "catch a ride".
Economic and cultural value
of the southern African Boraginaceae species are edible, but not
very tasty. Some species are browsed by game. A tea is made from
the dried leaves, stalks and berries of Ehretia rigida subsp.
nervifolia. Dried, ground root powder mixed with cold water
is used for diarrhoea (Trichodesma angustifolia subsp. angustifolia).
Leaves of Lobostemon, (with pretty bell-shaped flowers) fried
in sweet oil and leaf decoctions are old Cape remedies for ringworm,
sores, ulcers, burns and wounds (Joffe 2001).
In the Garden
Plants are easily propagated from seed or cuttings. The horticultural
potential of many southern African species of this family is still
to be explored.
Reference and further reading
- Joffe, P. 2001. Creative gardening with indigenous plants:
a South African guide. Briza Publications, Pretoria.