list of figures - Terry Sunderland

sloughing of the sheath spines particularly on drying, leaving bare sheaths. However,
these sloughed spines may leave faint, yet distinct, scars.
The total absence of spines on the sheath of Eremospatha is a characteristic feature of
this genus.
1.2.8 Indumentum
Between the spines on the sheath (where they occur) a thin covering of scales or
indumentum is a characteristic feature of nearly all of the endemic rattan genera in
Africa, particularly on the young or developing stems. In both Laccosperma and
Eremospatha, this indumentum is often dark brown to black and non-waxy, and in
Oncocalamus, the indumentum is white and somewhat waxy. Calamus deërratus does
not possess a distinctive indumentum.
1.2.9 The ocrea
At the mouth of the sheath where it narrows into the petiole or leaf rachis, there is
often a prolongation of the main part of the sheath. Often this prolongation is tubular
and encloses the sheath of the leaf above. This is called an ocrea. The ocrea may be
long, papery and prone to tattering as in Laccosperma, or may be short, saddle-shaped
and more truncate, as in Oncocalamus and Eremospatha. Calamus deërratus
possesses an ocrea that is intermediate between these two. The ocrea of two species of
Eremospatha, E. wendlandiana and E. barendii, are conspicuously longitudinally split
on the opposite side to the leaf. The resulting cleft is also rather prone to drying.
A number of species of Eremospatha, (E. macrocarpa, E. wendlandiana and E.
hookeri) also possess a distinctive linear “wrinkle” or narrow ridge, on the ocrea
facing the leaf. This wrinkle is particularly evident in the juvenile growth stages. This
morphological feature is not encountered elsewhere in the Calamoideae and is unique
to the African rattan taxa.
1.2.10 Sheath striations
Striations on the leaf sheath are a common feature of Eremospatha, Laccosperma and
are also possessed by some members of Oncocalamus. The leaf sheaths of Calamus
deërratus are not striate.
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