Kyllinga beninensis (Cyperaceae), a New Species from Bénin

Abstract

Kyllinga beninensis Samain, Reynders & Goetghebeur, a new species of Cyperaceae from the Borgou-Sud region of Bénin, is fully described and illustrated. This species can be recognized by the slender habit with swollen stem base, the tiny white head consisting of a single spike, and the spikelets with two glumes and one flower. Morphological differences with the species K. microbulbosa Lye from East Africa, to which K. beninensis bears a superficial resemblance, are discussed.

Full text

Kyllinga beninensis (Cyperaceae), a New Species from Be
´
nin
Marie-Ste
´
phanie Samain, Marc Reynders,* and Paul Goetghebeur
Ghent University, Department of Biology, Research Group Spermatophytes, K. L. Ledeganck-
straat 35, B-9000 Gent, Belgium. MarieStephanie.Samain@UGent.be;
Marc.Reynders@UGent.be; Paul.Goetghebeur@UGent.be. *Corresponding author
ABSTRACT . Kyllinga beninensis Samain, Reynders &
Goetghebeur, a new species of Cyperaceae from the
Borgou-Sud region of Be
´
nin, is fully described and
illustrated. This species can be recognized by the
slender habit with swollen stem base, the tiny white
head consisting of a single spike, and the spikelets
with two glumes and one flower. Morphological
differences with the species K. microbulbosa Lye from
East Africa, to which K. beninensis bears a superficial
resemblance, are discussed.
Key words: Be
´
nin, Cyperaceae, Kyllinga.
Since 1997, botanists of both the National Univer-
sity of Be
´
nin and Wageningen University (The
Netherlands) have been cooperating on the ‘‘Projet
d’ame
´
nagement d’un Herbier National et de re
´
daction
de la Flore Analytique du Be
´
nin.’’ One of the aims
of this project is the publication of a flora for Be
´
nin.
In a recent study of the Cyperaceae for this flora
(Samain & Goetghebeur, 2006), an enigmatic spe-
cimen of Kyllinga Rottbøll was noticed. After
identification attempts with several keys for African
species of Kyllinga (Hooper, 1972; Haines & Lye,
1983; Scholz & Scholz, 1983), it became evident that
we had discovered a new species in the genus
Kyllinga.
Kyllinga beninensis Samain, Reynders & Goetghe-
beur, sp. nov. TYPE: Be
´
nin. Borgou, Tchaourou,
Ouari-Maro, 27 Aug. 1999, B. Sinsin 3038
(holotype, WAG). Figures 1, 2.
Herba perennis tenuis; basis culmi tumida. Bracteae
involucrales 2–3; spica solitaria terminalis, ovoidea ad
globosa; spiculae numerosae. Spicula constans biglumosa
et uniflora; glumae albidae ad stramineae, translucidae ubi
maturae, obtusae ad apicem. Achenium lateraliter bicon-
vexum, complanatum, ellipsoideum, ferrugineum ad badium,
papillosum seriebus longitudinalibus, obtusum ad apicem,
interdum basi styli persistentis ut apiculo brevi.
Small, perennial herb with a swollen stem base 2–
3 mm thick, covered by persistent red-brown scales,
stems few together, loosely connected (Fig. 1A, B);
culms 10–20
6 0.02–0.04 cm, angular with rounded
ribs, glabrous (Fig. 1C). Leaves basal, laminae well
developed, 1.5–6 cm, linear, enrolled when dry,
scabrid on edges near top (Fig. 1D). Inflorescence
capitate, consisting of a single white, ovoid to globose
spike, 2–5 mm, with many spirally placed spikelets
(Fig. 1E); receptacle narrowly ovoid to cylindrical,
to 1
6 0.5 mm (Fig. 1F); involucral bracts 2 or 3,
spreading or slightly reflexed, scabrid on edges and
underside of midrib near the top, V-shaped in cross
section, largest bract 1–3 cm, second bract 0.5–
1.2 mm. Spikelet 1–1.3 mm, consisting of 2 glumes
and 1 flower (Fig. 1G, 2A); glumes white or straw-
colored, translucent when mature, 1–1.3 mm; glume
midrib straw-colored, raised, glabrous, with obtuse
apex; nerves on each side of the midrib 2 or 3, raised
and straw-colored. Nutlet biconvex, laterally flat-
tened, ellipsoidal with asymmetrical attachment, 0.9–
1.1
6 0.4–0.5 mm, light to dark brown, surface with
small papillae in longitudinal rows, apex obtuse, base
of the style sometimes remaining as a short apiculus
(Fig. 1H, I; 2B, C).
The genus Kyllinga can easily be distinguished
from other Cyperaceae by its headlike inflorescence,
small and few-glumed spikelets, and laterally com-
pressed nutlets with two style branches (Getliffe,
1983; Goetghebeur, 1998; Tucker, 1984). These
reduced characters result in a strong similarity among
the different species and a difficult taxonomy of the
genus. Vegetative characters such as stolons, rhi-
zomes, stem bases with persistent leaf sheaths, and
leaf and culm characteristics are very important to
distinguish the different species of Kyllinga. Un-
fortunately, these structures are often not collected so
that many collections can hardly be identified with
certainty.
Identification of the specimen with the Flora of
West Tropical Africa key(s) (Hooper, 1972) gives
Kyllinga echinata S. S. Hooper. This species,
however, has larger spikes 8–10 mm wide, old leaf
sheaths that decay into black fibers, and long-tipped
spikelets. Using key(s) in Scholz and Scholz (1983)
brings us to K. nigritana C. B. Clarke, which has
reddish glumes (when dry) with a wide ciliate wing
(not present on the specimen). Identification key(s) in
The Sedges and Rushes of East Africa (Haines & Lye,
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NOVON 16: 516–519. PUBLISHED ON 00 xX 2006.

1983) lead to K. microbulbosa Lye. The resemblance
is rather good, but K. microbulbosa has much larger
glumes and spikelets with more flowers per spikelet
than the novel specimen from Be
´
nin (Lye, 1972). Key
distinguishing morphological features of these two
species are given in Table 1.
Kyllinga beninensis is characterized by the slender
habit and swollen stem base. The white head with
Novon novo-16-04-18.3d 7/11/06 17:05:42 517 Cust # 2004191
Figure 1. Kyllinga beninensis Samain, Reynders & Goetghebeur. —A. Habit. —B. Swollen stem base. —C. Culm section.
—D. Leaf tip. —E. Inflorescence. —F. Receptaculum. —G. Spikelet. —H. Fruit, upper view. —I. Fruit, lateral view.
(Drawn from the holotype, Sinsin 3038, WAG, by Marc Reynders.)
Volume 16, Number 4 Samain et al. 517
2006 Kyllinga beninensis from Be´ nin

a single spike, the small spikelets with only two
glumes that lack appendages, and the achene with
papillae in longitudinal rows are other important
characters of this species.
The Borgou-Sud region in Be
´
nin, where the only
known specimen of this new species was collected, is
the northern part of the Guineo-Sudanian transition
zone. This region is characterized by a mosaic of
woodlands, dense dry forests, and tree- and shrub-
savannas, and is the northern equivalent of the
miombo woodland south of the equator (Adjanohoun
et al., 1989; Houinato & Sinsin, 2001).
Acknowledgments. We express our gratitude to the
curator of the Herbarium Vadense (WAG). We thank
Marcel Verhaegen (BR) for the beautiful SEM images
and Jan Rammeloo, director of the National Botanical
Garden of Belgium, for his continuing effort in
supporting Belgian botanists.
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Table 1. Main distinguishing characters of Kyllinga
beninensis and K. microbulbosa (characters of K. microbul-
bosa after Lye, 1972).
K. beninensis K. microbulbosa
Spikelet length, mm 1–1.3 2–3
Glume length, mm 1–1.3 2–2.5
Flowers per spikelet 1 1 to 3
Figure 2. Kyllinga beninensis Samain, Reynders & Goetghebeur, SEM images. —A. Spikelet. —B. Nutlet. —C. Detail of the
surface of a nutlet. (Sinsin 3038, WAG.)
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