Cortaderia echinata H.P.Linder, 2017

Testoni, Daniel & Linder, H. Peter, 2017, Synoptic taxonomy of Cortaderia Stapf (Danthonioideae, Poaceae), PhytoKeys 76, pp. 39-69 : 57-61

12. Cortaderia echinata H.P.Linder sp. nov. Figs 3G , 4A-G

Type.

Peru, vicinity of Cerro Ayrahnanca pass ca. 1 km E of Lugo Ututo on road between Cataparaco and Utcuyau, 4223 m. Rocky slopes, 11 Mar 2008, P. M. Peterson, R. J. Soreng, M. I. la Torre & J. V. Rojus Fox 21587 (holotype: Z!, isotype: US!).

Diagnosis.

Similar to Cortaderia pungens by the small compact habit and pungent leaves, but differing by the shattering leaves and the longer spikelets.

Description.

Plants forming tough, perennial cushions (vegetable hedgehogs) to 30 cm in diameter and to 30 cm tall. Basal sheaths white, shiny, persistent, when old splitting transversely into segments, puberulous between the veins. Ligule a dense ring of hairs 2-3 mm long, sheath mouth glabrous. Leaf blades 80-150 × 2-3 mm; C-shaped at base and margins incurved towards apex, forming a rolled, viciously pungent tip; disarticulating from the persistent sheath at the ligule. Inflorescence paniculate, contracted, ovate, 60-100 × 15-25 mm, with 100-300 spikelets; branches and pedicels shorter than and obscured by the spikelets, scaberulous. Female-fertile spikelet 16-22 mm long; with ca. 3 florets. Glumes 16-22 × 0.6-0.8 mm; twice as long as the packet of florets; 1 veined, acute, glabrous, straw to almost white, upper and lower glumes similar. Callus ca. 0.75 mm long; indumentum 2-2.5 mm long, overtopping the base of the lemma hairs length; rhachilla 0.75 mm long. Second lemma ca. 4 mm long, 5 veined, indumentum scattered on lower half of lemma back, about as long as the lemma lobes, 5-6 mm long; lemma-lobes acute, 3-4.5 mm long, setae 2-3 mm long, distinctly shorter than lemma lobes, included in the glumes; awn simple, 8.5-10 mm, longer than setae. Palea linear, 5 × 0.5 mm, obscurely bilobed, keels sinuose; scabrid, with hair-tufts along mid-margins. Lodicules obtriangular and with bristles.

Leaf anatomy.

Leaf in transverse section expanded, sclerophyllous; margins gently tapering, sclerenchyma caps well-developed; adaxial furrows located between all vascular bundles, the same over primary and tertiary vascular bundles, about half depth of leaf, forming narrow clefts, ribs flat-topped; abaxial ribs and furrows present. Vascular bundles closer to abaxial surface, 3 primary vascular bundles in half a leaf section, with 1-2 tertiary vascular bundles between the primary vascular bundles. primary vascular bundles elliptical; phloem without lignified cells; metaxylem vessels narrower than outer bundle sheath cells; outer bundle sheath clearly distinct from chlorenchyma, cells larger and colourless, with adaxial and abaxial interruptions; inner bundle sheath walls thickened anticlinally, cells smaller than outer bundle sheath cells; adaxial sclerenchyma as inversely anchor-shaped girders; abaxial sclerenchyma as trapezoidal girders. tertiary vascular bundles outer bundle sheath cells distinct from and larger than chlorenchyma cells, walls thickened anticlinally or all round; with abaxial interruption only; adaxial bundle sheath extension present with cells smaller than outer bundle sheath cells; adaxial sclerenchyma inversely anchor-shaped girders; abaxial sclerenchyma as trapezoidal girders; phloem without lignified cells or with only the inner bundle sheath lgnified. Mesophyll of small, angular isodiametric chlorenchyma cells with small air spaces. Abaxial epidermal cells all larger than adaxial ones; outer wall twice as thick as inner wall; walls equal to mesophyll walls. Subepidermal layer of sclerified fibres only in marginal regions of leaves, absent from the middle of the leaf (directly next to leaf margins), 2-3 cells thick; with large clear parenchymatous cells below abaxial furrow present, connected via collenchyma cells to the adaxial furrow to the epidermis and so partitioning the chlorenchyma. Bulliform cells absent; abaxial epidermal zonation present (Fig. 3G ).

Etymology.

echinus (Latin) = hedge-hog or sea-urchin. The plant is spiny like a hedgehog.

Distribution and ecology.

South America, Peru.

Altitude.

4220-4230 m.

Habitat.

Rock ledges (bedrock slabs); moisture regime: in soil pockets on rock. Forming cushions on almost flat rock slabs, in pockets of soil.

Conservation status.

Known only from the type collection.

Phenology.

Flowering month March or April.

Taxonomy.

The small compact hedgehog form with pungent leaves is similar to Cortaderia pungens , from which it differs by the shattering leaves and the longer spikelets (glumes 15-25 mm long). The shattering leaf-sheaths link the species to Cortaderia boliviensis , but it differs by the very different growth form. The compact inflorescences are reminiscent of Cortaderia egmontiana , but the pungent leaves provide a simple diagnostic difference.

The leaf anatomy is reminiscent of that of Cortaderia bifida , but the outer bundle sheath is not lignified, and form an extension adaxially on the vascular bundles, connecting them to the lignified anchor-shaped girders.

Figures

Figure 3. Leaf anatomy of Cortaderia, as evident from transverse sections. A Cortaderia egmontiana (Moore 2677) B Cortaderia modesta (Glaziou 17913) C Cortaderia hieronymi (Garcia 563) D Cortaderia nitida (Laegaard 53121) E Cortaderia boliviensis (Beck 11273); F Cortaderia sericantha (Ramsay 967); G Cortaderia echinata (Peterson 21587) H Cortaderia bifida (Renvoize 4202) I Cortaderia hapalotricha (Laegaard 53305) J Cortaderia roraimensis (Maguire 60448). Structures referred to in the descriptions are labelled as follows: 1, multi-layered abaxial sub-epidermal collenchyma layer; 2, adaxial islands of collenchyma in the abaxial grooves; 3, chlorenchyma; 4, primary vascular bundle; 5, midrib.

Figure 4. Cortaderia echinata (all from Peterson 21587). A habitat on bare rock slabs B habit, forming a vegetable hedgehog C inflorescence D spikelet, somewhat squashed (all very compact in the inflorescence) E glumes F floret package, with three florets, note long lemma indumentum G palea with sparse indumentum on the lateral palea flaps. A and B were photographed by Paul Peterson and Robert Soreng.