Ichnanthus

Ichnanthus is a genus of herbaceous plants belonging to the Poaceae family. It is native to tropical West Africa. It comprises 155 described species and of these, only 33 accepted.

Description

They are annual or perennial plants; with frequently decumbent stems at the lower nodes; hermaphrodite plants. Frequently stem leaves, sometimes basal; ligule a sparse to densely ciliated membrane; blades lanceolate to ovate, flattened, often with a narrow, asymmetric base, pseudopetiolate or sessile. Inflorescence a simple or compound panicle, usually one terminal and conspicuously exserted from the upper sheath, in some species with 1–several less exsert axillary panicles; spikelets lanceoloide, paired, unequally pedicelate, dorsally compressed but with prominently carinate glumes so that in many species they appear laterally compressed, with 2 florets; disarticulation below glumes and sometimes below upper floret; glumes unequal, keeled, the lower glumes usually more than 1/2 the length of the spikelet; upper glume and lower lemma nearly equal, longer than upper floret, herbaceous; lower floret sterile or staminate; lower palea membranaceous; upper floret bisexual, dorsally compressed; upper lemma hardened, the rachilla continues below the lemma forming a small pedicel; pedicel with membranaceous appendages adnate at lemma base and free above (often thickened with oil at maturity), or appendages reduced to small sclerotic areas or scars at lemma base; lodicules 2; stamens 3; styles 2. Fruit an ovoid to ellipsoid caryopsis; embryo 1/3–1/2 length of caryopsis, stippled thread.

Taxonomy

The genus was described by Ambroise Marie François Joseph Palisot de Beauvois and published in Essai d'une Nouvelle Agrostographie 56, pl. 12, f. 1. 1812. The type species is: Ichnanthus panicoides P. Beauv.

Cytology

Number of chromosomes: 2n = 18, 20, 40, and 54.

Etymology

Ichnanthus: generic name derived from the Greek word: chnos (a step or mark), perhaps referring to the appendages below upper foil.

Species

• Ichnanthus amplus Swallen
• Ichnanthus angustifolius Swallen
• Ichnanthus angustus Swallen
• Ichnanthus annuus Killeen & Kirpes
• Ichnanthus areolatus K.E.Rogers
• Ichnanthus attentuatus K.E.Rogers
• Ichnanthus boliviensis K.E.Rogers
• Ichnanthus brevivaginatus Swallen
• Ichnanthus candicans Doell.
• Ichnanthus confertus K.E.Rogers
• Ichnanthus drepanophyllus Mez
• Ichnanthus exilis K.E.Rogers
• Ichnanthus hitchcockii K.E.Rogers
• Ichnanthus lanceolatus Scribn. & J.G.Sm.
• Ichnanthus latifolius K.E.Rogers
• Ichnanthus leptophyllus Doell.
• Ichnanthus neblinaensis Swallen
• Ichnanthus neesii K.E.Rogers
• Ichnanthus nemoralis
• Ichnanthus nemorosus (Sw.) Doell.
• Ichnanthus pilosus K.E.Rogers
• Ichnanthus ruprechtii Doell.
• Ichnanthus serratus Swallen
• Ichnanthus tectus Swallen
• Ichnanthus tipuaniensis K.E.Rogers
• Ichnanthus vestitus Swallen
• Ichnanthus wrightii Hitchc.