Ischaemum barbatum Retz.
Ischaemum L., Sp. Pl. 1: 1049 (1753); Gen. Pl. 5th edn, 469 (1754); from the Greek ischo (to restrain) and haima (blood), as woolly seeds of the type species were reported as being used to stop bleeding.
barbatum- Latin for bearded or barbed. With hairs on the callus, glumes or lemma.
Observ. Bot. 6: 35 (1791).
Perennial. Culms erect or geniculately ascending, 60160 cm tall. Mid-culm nodes glabrous. Lateral branches simple. Ligule an eciliate membrane, 23.5 mm long. Leaf-blades 720 cm long, 410 mm wide.
Inflorescence with ramose branches. Rames single or paired, 59 cm long. Rhachis fragile at the nodes, angular, ciliate on margins. Rame internodes columnar, 45 mm long, flat and forming a U or V shape with the pedicel in rear view. Rame internode tip transverse, cupiliform.
Spikelets in pairs, one sessile and fertile and the other (companion) spikelet pedicelled. Pedicels columnar, 12 mm long, ciliate. Companion spikelets developed, sterile, comprising 2 subequal glumes without lemmas or containing empty lemmas or male, asymmetrical, oblong, 46 mm long, as long as fertile, separately deciduous. Companion spikelet glumes chartaceous, winged on keels, muticous. Companion spikelet lemmas 2, enclosed by glumes, muticous. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret male, upper fertile, without rhachilla extension, elliptic or oblong, dorsally compressed, 5.58 mm long, falling entire, deciduous with accessory branch structures. Spikelet callus square, glabrous or pubescent, base truncate, inserted.
Glumes dissimilar, firmer than fertile lemma. Lower glume oblong, asymmetrical, 100% of length of spikelet, membranous or coriaceous or indurate, much thinner above, 2-keeled, keeled laterally, narrowly winged on keel, winged near apex or above, 1315-nerved. Lower glume lateral nerves obscure. Lower glume surface convex. Lower glume surface muricate or rugose, rough below or on flanks. Lower glume apex acute. Upper glume lanceolate, 57 mm long, coriaceous, much thinner above, 1-keeled, 3-nerved. Upper glume surface glabrous. Upper glume margins ciliate. Upper glume apex acute or acuminate.
Basal sterile floret 1, with palea. Lemma of lower sterile floret lanceolate, 46 mm long, 75% of length of spikelet, hyaline or membranous, 3-nerved, acute. Fertile lemma linear or oblong, 45 mm long, membranous, 3-nerved. Lemma apex lobed, 2-fid, with linear lobes, incised 2575% of lemma length, 1-awned. Median (principal) awn from a sinus, geniculate, 915 mm long overall, with a twisted column. Column glabrous. Palea linear, 45 mm long, 100% of length of lemma. Grain 1 mm long.
Africa, Temperate Asia, Tropical Asia, Australasia.
Northern Territory: Darwin & Gulf.
Habit and inflorescence (line drawing)
© Queensland Herbarium
by Will Smith