Cyperus papyrus L., post 2 of 2, taxonomy and distribution

Cyperus papyrus is a tall and graceful plant.  It looks stunning in the Tropical Greenhouse with a tropical blue sky behind it, which, even in October, Reading obligingly provided, to prove the point.  It’s up to 5m tall, with almost globular flower heads which have a complex structure…

This is the second of two posts about Cyperus papyrus, it covers this intriguing plant’s taxonomy and distribution.  The first post discusses its immense value and fascinating uses, both old and new.

Cyperus papyrus in the Reading Tropical Greenhouse.

How do we identify it? This species can grow up to 5m tall, much taller than our plant at the moment.  It grows in shallow water around lakes and alongside rivers.  Its most prominent features are the solid, triangular (typical Cyperaceae or sedge family) flower stalks (culms) up to 6cm across at the base, and the large, almost globular inflorescences, which are complex to describe.

C. papyrus inflorescences, ± 50cm in diameter.

The very smooth, glossy culms taper, and bear an umbel-like inflorescence.   Each inflorescence has 4-8 basal bracts and 50-100 (occasionally up to 150) prominent, very thin, green, branches, 10 to 50cm long, which have tubular, reduced leaves at their bases.    The branches elongate and eventually bear (not always) numerous flower spikelets in clusters on 3-5 short secondary branches.  The inflorescence becomes almost spherical as the branches elongate and the outer ones droop.

C. papyrus, long, green bracteoles emerging from beneath clusters of secondary branches, each bearing numerous spikelets. (Spikelet length ± 2cm).

The spikelets, each with 6-16 flowers, are less than 0.5cm long and have 3-5 basal bracteoles, which are thin, leaf-like and extend up to 10cm further, making the inflorescence seem much larger, rounder, and more elegant in appearance.

Its flowers are in a distichous arrangement in the spikelets, each has a glume 1.2-2mm wide by 1-1.3mm long, one glume per flower is a diagnostic Cyperus feature.  For a full description, see Boulos, 2005.

Left: C. papyrus spike, ± 1.5cm long, still attached to the rachis, showing the arrangement of florets. Right: two florets, one with a nutlet and its single subtending glume (below), and the other nutlet separated from the glume. Glumes are ± 1.5mm long. The typical Cyperaceae nutlets have the stigmas protruding apically.

Here is a close up of the leaf sheath (far left) clearly showing a split, this is on the ventral side.  Leaves are in ranks of three, though this is very difficult to observe, given that they’re reduced to these papery sheaths.  Top right is a culm cross-section, the trigonous outline, so typical of Cyperaceae, stands out, and the tissue comprises mainly spongy parenchyma (pith) and scattered vascular bundles, a typically Monocot. arrangement.  Bottom right, is a longitudinal stem section, showing elongated fibres which are responsible for resilience when it’s made into paper.

Where does it grow?  Cyperus papyrus grows as a native throughout tropical Africa, including Madagascar and the Mascarene Islands of the Indian Ocean (Boulos 2005).  IUCN (Kumar 2011) has incomplete records for Africa, but extends its introduced range to include India (Gujarat, Rajasthan), Indonesia, Israel, Sri Lanka, Syrian Arab Republic, and Taiwan, Province of China.   It has also been introduced and is naturalised in Sicily and elsewhere (Terer et al. 2012).  In the wild it grows along streams and in shallow lakes and can clog up waterways.  It is widely known for becoming invasive and dominant to the exclusion of other species, given the right conditions, and has even done so in parts of theUSA (Serag 2003).  This is achieved thanks to its underwater, creeping rhizomes, and although it produces seed, this is said to be a sporadic means of reproduction (Boulos 2005).

Interestingly, it reputedly disappeared from the Nile region, presumably due to over-harvesting, as French explorers failed to find it there at the end of the 18th century (Hakuno 2005, Parkinson and Quirke 1995).  It was later re-introduced to gardens inCairo,  from the Paris Botanical Gardens and it was also re-introduced to the Egyptian Nile in 1969, fromSudanandEthiopia, “to revive the art and industry of making papyrus” (Serag 2003, p. 15).  However, in 1971, it is reported that a small colony of 20 plants was found at the Umm RishaLakein the Wadi El- Natrun Depression,Egypt, the only site for it inNorth Africa.  So, either it never died out entirely or else it was re-introduced there (notably, this is a well known location for birds).

Near British relations:  C. fuscus (Brown Galingale) and C. longus (Galingale). 

The only Cyperus papyrus relative I’ve seen, in the wild is C. fuscus, because one of its stations is in the Gordano Valley, just a few miles outside Bristol; it’s a rare plant, tiny (only a few cm high), and annual.  C. longus is a larger (still only about 30cm) perennial species, more widespread, though still uncommon.  A few other species have also escaped from captivity here, and occasionally become naturalised.

Nomenclature, Classification & Taxonomy  Cyperus papyrus is an “L-Dot” species, which means it was named by Linnaeus – in the first volume of his seminal work Species Plantarum published in 1753.  The name has withstood the attentions of the botanical community since, and is still in use, which suggests that it was, and remains, a robust species definition.

The Cyperaceae has also remained stable (Stevens 2001 onwards).  Epidermal silica bodies and characters of the pollen confirm a monophyletic delineation.  They’re almost all herbaceous, but a few shrubs and lianas creep in.  It’s a large family, in the order “Poales” which includes Poaceae (grasses) and Juncaceae (rushes).  It has about 4,500 species in 100 genera.  1500 species are in Carex and 700 in Cyperus.

Cyperus is distinguishable from Carex by its umbel-like, terminal inflorescences with at least some bisexual flowers, in every spikelet.  Carex has unisexual flowers, variously arranged inflorescences, and notably glumes (bracts) fused around the nutlet into a flask-like utricle. Each Cyperus flower has only one glume.

The picture for taxa between family and genus is quite complicated.  Cyperus seems to actually comprise about 13 genera, i.e. it’s a polyphyletic genus.  When the 12 other genera are eventually moved, about 650 species may remain.  So, unsurprisingly, Cyperus has historically been divided into subgenera and sections (Huygh et al. 2010, Larridon et al. 2011, Reynders et al. 2011).

A great deal of effort has been expended recently to resolve the confusions, mistakes and complexity that arise from the subdivision of this genus, nevertheless no less than 165 legitimate subdivisions are still recognised.  We haven’t heard the last of it yet, not by a long way.  Much of the debate centres on a just a small number of critical characters, for example whether a species’ anatomy is adapted for C3 or C4 chemistry (Huygh et al. 2010, Larridon et al., 2011, Reynders et al. 2011).  The experts recognise that a re-classification of Cyperus is urgently needed but the sound, molecular, phylogenetic basis for one does not yet exist.

One of the mob?  The plant in our greenhouse is one of the recognised subspecies, but I don’t know which one (and there’s no record).  There’s also been an awful lot of chopping and changing of Cyperus papyrus at the infraspecific level.  Kew’s online Plant List (The Plant List, 2010) currently accepts ssp. madagascariensis (Willd.) Chiov., ssp. nyassicus (Chiov.) Kük., and ssp. zairensis (Chiov.) Kük., as well as the type, while relegating 10 other names of subspecies or varieties to synonymy.

Cyperus papyrus, near Syracusa, Sicily, 2011

Tournay, in 1950, reports that the only plants Linnaeus saw were from Sicily, and so nominated an Italian specimen as a lectotype.  Consequently, if the subspecies delimitations are ever reviewed, and judging by the synonymy and age of the most recent study there’s a need for it, African papyrus, like African Acacia’s, could end up, because of the Sicilian connection, with a new name.  A delve into the α-botany papers is needed to find out more, and to identify our plant.

The possibly native Egyptian plants found at Umm Risha Lake in Egypt (see above) were identified as C. papyrus subsp. antiquorum (Serag 2003), which is a synonym of C. papyrus subsp. niliacus var. niliacus  (Tournay) (Tournay 1950).  Kew, however, does not recognise subsp. niliacus as an accepted name.  The identity of the Paris Botanical Garden re-introduction is unknown, and the Sudan and Ethiopia re-introduction was given as C. cyperus. L. (Serag 2003).  So we don’t really know what papyrus is growing in Egypt now, or even if there’s just one kind.

Attributions

All photographs were taken by P. Rooney and may be used freely. Except:  Cyperus in Sicily  Some rights reserved by Marchal.  BSBI, 2012 distribution of C. fuscus; and the Royal Horticultural Society’s Award of Garden Merit logo which is Trade Marked.

References

Archer, C. 2004. Website: http://www.plantzafrica.com/plantcd/cyperuspap.htm, South African National Biodiversity Institute,South Africa., Accessed 14/10/2012.

Boulos L. 2005. Flora of Egypt: volume 4. Monocotyledons Alismataceae – Orchidaceae.Cairo: Al Hadara Publishing.

Hakuno, D., 2005. Medicinal Plants and Phytomedicines. In: The Cultural History of Plants. (Consulting Editor: Ghillean Prance, Scientific Editor: M. Nesbitt). Taylor andFrancis,New York, Routledge, pp. 205–238

Heyerdahl, T. 1970.  The Ra Expeditions. Billing & Sons, Guildford & London.

Heywood, V. H., Brummitt, R. K., Culham, A., & Seberg, O., 2007. Flowering plant families of the world. RoyalBotanic Gardens,Kew.

Online Parallel Bible Project. Website: http://bible.cc/exodus/2-3.htm.  Accessed 14/10/2012.

BSBI, 2012. Botanical Society of the Bristish Isles.  Website: http://www.brc.ac.uk/plantatlas/index.php?q=plant/cyperus-fuscus.  Accessed 14/10/12.

Huygh, W., Larridon,I., Reynders, M., Muasya, A., Govaerts, R., Simpson, D., Goetghebeur, P. 2010. Nomenclature and typification of names of genera and subdivisions of genera in Cypereae (Cyperaceae): 1. Names of genera in the Cyperus clade. Taxon, Volume 59, Number 6, pp. 1883-1890(8).

Kumar, B. 2011. Cyperus papyrus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. <www.iucnredlist.org>.  Accessed 14 /10/2012.

Larridon,I., Huygh, W., Reynders, M., A. Muasya, A., Govaerts, R., Simpson, D., Goetghebeur, P. 2011. Nomenclature and typification of names of genera and subdivisions of genera in Cypereae (Cyperaceae): 2. Names of subdivisions of Cyperus.  Taxon, Volume 60, Number 3, pp. 868-884(17).

Parkinson, R. and Quirke, S. 1995. Papyrus. Austin:University ofTexas Press.

Parsons, J. L. 1949. Some interesting facts about paper. Journal of Chemical Education  26 (2), 114.

Purseglove, J.W., 1972. Tropical Crops Monocotyledons. Longman.

Reynders, M., Huygh, W., Larridon,I., Muasya, A.; Govaerts, R., Simpson, D., Goetghebeur, P. 2011. Nomenclature and typification of names of genera and subdivisions of genera in the Cypereae (Cyperaceae): 3. Names in segregate genera of Cyperus. Taxon, Volume 60, Number 3, pp. 885-895(11).

RHS 1.  Royal Horticultural Society. 2012. Website: http://apps.rhs.org.uk/rhsplantfinder/pfregions.asp?ID=5206.  Accessed 14/10/2012.

RHS 2. Royal Horticultural Society. 2012. Website: http://apps.rhs.org.uk/plantselector/plant?plantid=5926.  Accessed 14/10/2012.

RHS 3. Royal Horticultural Society. 2012.  Website: http://apps.rhs.org.uk/plantselector/plant?plantid=4429.  Accessed 11/10/2012.

Serag, M. S. 2003. Ecology and biomass production of Cyperus papyrus L. on the Nile bank at Damietta, Egypt. Journal of Mediterranean Ecology, 4, 15-24.

Stern,W.T., 1992. Dictionary of Plant Names for Gardeners. Cassell Publishers.

Stevens, P. F., (2001 onwards). Angiosperm Phylogeny Website. Version 12, July 2012 [and more or less continuously updated since]. http://www.mobot.org/MOBOT/research/APweb/. Accessed 23/10/2012.

Terer, T., Triest, L., Muasya, AM. 2012. Effects of harvesting Cyperus papyrus in undisturbed wetland Lake Naivasha Kenya. Hydrobiologia 680:135–148.

Tournay, R. 1950. La Nomenclature et la Synonymie des sous-espèces de Cyperus papyrus L.. Bulletin de l Société Royale de Botnique de Belgique, Tome 82, p.345.

The Plant List (2010). Version 1. Published on the Internet; website: http://www.theplantlist.org/.  Accessed 10/10/2012.

Twesigye, J.  2012.  Pers. comm. on behalf of Rwanda Ministry for Infrastructure.