Carex sect. Spirostachyae explained

Carex sect. Spirostachyae is a section of the genus Carex, containing 38 species of sedge. Species in Carex sect. Spirostachyae share a suite of features, including the short internodes of the primary rhizomes, the presence of an antiligule, the leaf-like, sheathing bract at the base of the inflorescence, the presence of three stigmas in female flowers, and the shape of the seeds.^[1]

The section is composed of two subsections, with differing edaphic preferences; subsection Elatae comprises species that lives on acidic soils, while those in subsection Spirostachyae live on basic or ultramafic soils.^[1] The two sections also differ morphologically, with species in subsection Elatae having wider leaves, thicker stems and larger spikes, the lowest of which may hang downwards.^[1]

The centre of diversity of the group is in Europe and adjacent parts of Africa and Asia; a few species occur in Australia, Africa, South America and on oceanic islands.^[1] The three species present in North America are introductions.^[2]

Subsection Elatae (Kük.) Luceño & M. Escudero

• Carex aethiopica Schkuhr – South Africa
• Carex binervis Sm. – western Europe
• Carex borbonica Lam. – Mascarene Islands
• Carex boryana Schkuhr – Mascarene Islands
• Carex camposii Boiss. & Reut. – southern Spain
• Carex catharinensis Boeck. – southeastern Brazil
• Carex clavata Thunb. – South Africa
• Carex cyrtosaccus C. B. Clarke – Tanzania, Malawi
• Carex elgonensis Nelmes – Mount Elgon
• Carex fischeri K. Schum. – central Africa
• Carex fissirostris Ball – Atlas Mountains, Morocco
• Carex fuscula d'Urv. – Chile, Argentina
• Carex gunniana Boot. – southeastern Australia
• Carex helodes Link – southern Spain and Portugal, northern Morocco
• Carex hochstetteriana J. Gay ex Seub. – Azores
• Carex laevigata Sm. – western Europe, Morocco
• Carex petitiana A. Rich. – central Africa
• Carex lowei Bech. – Madeira
• Carex mairii Coss. & Germ. – France, Spain, northern Morocco
• Carex mannii E. A. Bruce – central Africa
• Carex mildbraediana Kük. – Rwanda, Burundi, Kenya
• Carex modesti M.Escudero, Martín-Bravo & Jim.Mejías – Tanzania^[3]
• Carex paulo-vargasii Luceño & Marín – Morocco
• Carex perraudieriana J. Gay – Canary Islands
• Carex punctata Gaud. – Europe, Morocco, western Asia
• Carex simensis Hochst. ex A. Rich. – central Africa
• Carex thouarsii Carmich. – Tristan da Cunha
• Carex vallis-rosetto K. Schum. – Kenya, Tanzania

Subsection Spirostachyae

• Carex blakei Nelmes – southeastern Australia
• Carex burchelliana Boeck. – South Africa
• Carex diluta M. Bieb. – central and western Asia
• Carex distans L. – Europe, North Africa, central and western Asia
• Carex ecklonii Nees – South Africa
• Carex extensa Good. – Europe and Mediterranean Basin
• Carex idaea Greuter et al. – Crete
• Carex lainzii Luceño, E. Rico & T. Romero – central Spain
• Carex tasmanica Kük. – Tasmania
• Carex troodi Turril – Cyprus
• Carex vixdentata (Kük.) G. A. Wheeler – South America

Further reading

• Marcial Escudero . Virginia Valcárel . Pablo Vargas . Modesto Luceño . 2008 . Evolution in Carex L. sect. Spirostachyae (Cyperaceae): a molecular and cytogenetic approach . . 7 . 4 . 271–291 . 10.1016/j.ode.2006.08.006. free .

Notes and References

1. Marcial Escudero . Modesto Luceño . 2009 . Systematics and evolution of Carex sects. Spirostachyae and Elatae (Cyperaceae) . . 279 . 1–4 . 163–189 . 10.1007/s00606-009-0156-x. 29472803 .
2. Book: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=302736 . Carex Linnaeus sect. Spirostachyae (Drejer) L. H. Bailey in J. M. Coulter, Man. Bot. Rocky Mt. 381. 1885 . . 23 . Magnoliophyta: Commelinidae (in part): Cyperaceae . Peter W. Ball . A. A. Reznicek . David F. Murray . 2002 . . 978-0-19-515207-4 . 521–523.
3. S. Martín-Bravo . M. Escudero . P. Jiménez-Mejías . 2012 . Carex modesti (Cyperaceae), a new species from southern Tanzania . . 57 . 2 . 143–146 . 10.3767/000651912X657576. 11441/87930 . free .