Cortaderia Stapf
Type species: C. selloana (Schult. et Schult.f.) Asch. et Graebn.
Tall perennial tussocks with robust intravaginal shoots (extravaginal in C. splendens). Leaf-sheaths heavily coated in epicuticular wax or not, breaking into short segments or remaining entire. Ligule a rim of short hairs. Leaf-blade to 2 m long, tapering, 1-many evident ribs, scabrid and sharply cutting from many antrorse prickle-teeth or scarcely so, homo- or heterochromous. Panicle large, plumose, variously coloured subtended by long, hair-fringed bract, branches stiff to flexible. Glumes 1-nerved, transparent, minutely prickle-toothed. Spikelets with 3-7 florets. Flowers dimorphic on separate plants, ⚥ and ♀, gynodioecious. Lemma 3-nerved, hairs abundant and radiating (except on C. selloana ⚥) awned from between bifid lobes or entire and mucronate. Lodicules 2, cuneate and irregularly lobed, hair-tipped. Androecium of male-fertile flowers with 3 long anthers, of male-sterile flowers reduced to small staminodes or shorter sterile anthers. Gynoecium with 2 plumose stigmas (and the remnant of a third), ♀ > ⚥. Caryopsis free; hilum linear c. ½ caryopsis. Fig. 17.
Key
25 spp., most in South America from Venezuela to Chile and Argentina. Endemic spp. 5; naturalised spp. 2, from South America.
For names and types in Cortaderia see Connor, H. E. and Edgar, E. Taxon 23: 595-605 (1974) and Connor, H. E. Taxon 32: 633-634 (1983). DNA sequences reported by Barker, N. P., Linder, H. P. and Harley, E. H. Syst. Bot. 23: 327-350 (1998) indicated that New Zealand and South American spp. are not monophyletic.
The taxonomy here follows that of Zotov, V. D. N.Z. J. Bot. 1: 78-136 (1963) with the addition of taxa recognised since then.
Native species are collectively known as toetoe, and the naturalised species as pampas grass.