25.12   MELINIS P. Beauv.

REVISED TREATMENT. Please send comments to Mary Barkworth.
J.K. Wipff

Plants annual or perennial; habit various. Culms 20-150 cm, erect, decumbent, or prostrate. Sheaths open; ligules of hairs or membranous and ciliate. Inflorescences terminal, simple panicles or panicles of spikelike primary branches, usually with capillary secondary branches and pedicels; disarticulation below the glumes, sometimes also below the upper florets, the upper florets then falling first. Spikelets with 2 florets. Lower glumes present or absent, 0-1-veined, unawned; upper glumes equaling or exceeding the florets, sometimes gibbous basally, 5-7-veined, emarginate to bilobed, awned or unawned; lower florets staminate or sterile; lower lemmas similar to the upper glumes, but not gibbous; upper florets bisexual, laterally compressed; upper lemmas subcoriaceous, glabrous, smooth, unawned; upper paleas resembling the upper lemmas; lodicules 2, fleshy or membranous. x = 9. Name from the Greek meline, millet.

Melinis is an African and western Asian genus of 22 species that grow in savannahs, open grasslands, and disturbed places. Two species have become established in the Flora region. A third, M. nerviglumis, is now being marketed as an ornamental species and has been added to this treatment for that reason. The key leads and description are based on the treatment by H.M. Anderson (1991).

Rhynchelytrum Nees has traditionally been treated as a separate genus, with the number of veins being the diagnostic character. Zizka (1988) showed that this separation was artificial; consequently the older generic name, Melinis, is now applied to species that used to be included in Rhynchelytrum.


SELECTED REFERENCES Anderson, H.M. 1991. Melinis P. Beauv. Pp. 210-213 in G.E. Gibbs Russell, L. Watson, M. Koekemoer, L. Smook, N.P. Barker, H.M. Anderson, and M.J. Dallwitz. Grasses of Southern Africa (ed. O.A. Leistner). National Botanic Gardens, Botanical Research Institute, Pretoria, Republic of South Africa. 437 pp.; Zizka, G.1988. Revision der Melinideae Hitchcock (Poaceae, Panicoideae). Biblioth. Bot. 138:1-149; Zizka, G. 1990. Taxonomy of the Melinideae (Poaceae: Panicoideae). Mitt. Inst. Allg. Bot. Hamburg 23:563-572.

1
Glumes and pedicels glabrous, scabridulous; lower florets without paleas ..... 1. M. minutiflora
Glumes, and usually the pedicels, with hairs to 7 mm long; lower florets with paleas (2)
2
Leaf sheaths not strongly overlapping; leaves not rolled; plants usually annual ..... 2. M. repens
Leaf sheaths strongly overlapping; leaves rolled; plants usually perennial .....3. M. nerviglumis


1.   Melinis minutiflora P. Beauv.
Molasses Grass

Plants perennial; cespitose; aromatic. Culms (50)80-150 cm, branching and sprawling, often becoming matted, usually rooting at the lower nodes; upper nodes appressed pubescent; internodes glabrous basally, appressed pubescent distally. Sheaths densely tomentose, hairs 0.5-5.2 mm, spreading, papillose-based, often sticky and smelling of linseed oil; ligules of hairs, 1-2 mm; blades 3.5-19 cm long, 4-14 mm wide, flat, pubescent, hairs sometimes papillose-based. Panicles (4.5)7-20 cm long, 1-9.5 cm wide, narrowly ovate; primary branches to 8 cm; pedicels usually shorter than the spikelets, glabrous, scabridulous. Spikelets 1.7-2.4 mm, usually purplish; calluses glabrous. Lower glumes absent or to 0.3 mm, glabrous, scabridulous; upper glumes 1.6-2.4 mm, glabrous, unawned, sometimes muticous; lower florets sterile; lower lemmas bilobed, lobes 0.2-0.7 mm, unawned or awned, awns to 18 mm; lower paleas absent; upper lemmas 1.4-1.9 mm, glabrous; upper paleas 1.5-1.9 mm, usually slightly longer than the upper lemmas; anthers 3, 1-1.5 mm, reddish-brown to orange. Caryopses 0.9-1.2 mm long, 0.3-0.4 mm wide. 2n = 36.

Melinis minutiflora is native to Africa, but has been introduced throughout the tropics as a forage crop. It is now regarded as a serious weed in many places. In the Flora region, it is only known to be established in southern Florida.


2.   Melinis repens (Willd.) Zizka
Natal Grass

Plants annuals or short-lived perennials. Culms (20)40-150 cm, decumbent, usually rooting at the lower nodes; nodes pubescent; internodes glabrous or with papillose-based hairs, hairs to 4.7 mm. Sheaths glabrous or with papillose-based hairs, hairs 0.5-4.7 mm; ligules of hairs, 0.7-2.2 mm; blades 3.6-27 cm long, 2-9(14) mm wide, flat, glabrous or pubescent, with or without papillose-based hairs. Panicles (4)6-22 cm long, (1.5)2.5-12 cm wide; primary branches to 11 cm, ends of the primary branches, secondary branches, and pedicels capillary; pedicels 0.6-5.3 mm, usually hairy distally, hairs to 6.3 mm. Spikelets 2-5.7 mm; calluses hairy, hairs to 4 mm. Lower glumes 0-1.7 mm, pubescent, sometimes with papillose-based hairs, apices rounded, truncate, or slightly cleft; upper glumes (1.9)2.3-4.9 mm, enclosing the upper florets, gibbous basally, densely pubescent, hairs to 7 mm, sometimes papillose-based, varying from white to rose or darkish purple, apices tapering, beaked, glabrous, unawned or awned, awns to 4.1 mm; lower florets staminate or sterile; lower lemmas 1.9-4.8 mm, unawned or with awns to 4.2 mm; lower paleas 0.9-4 mm; anthers (0.8)1.5-2.6 mm, orange-brown to orange; upper lemmas 1.8-2.7 mm, glabrous; anthers 3, 1.2-1.7 mm, orange-brown to orange. Caryopses 1.3-1.9 mm long, 0.6-0.9 mm wide. 2n = 36.

Melinis repens is probably native to Africa and western Asia. It is now established throughout the subtropics, including the southern portion of the Flora region. It has been grown as an ornamental, but it is now established and often weedy in warmer portions of the region.

Plants in the Flora region belong to Melinis repens (Willd.) Zizka subsp. repens, one of four weakly-separated subspecies.


3.   Melinis nerviglumis (Franch.) Zizka

Plants perennial; cespitose. Culms (25)40-120(150) cm. Leaf sheaths not strongly overlapping; blades (3)1-30(44) cm long, (1.3)2-3.5(4.5) mm wide, rolled. Panicles contracted. Pedicels scabrous, with hairs to 7 mm. Spikelets 3.2-5.7 mm long, 2 mm wide, often densely covered with hairs, hairs to 4 mm, white or pink to purple. Glumes separated by 0.3(0.6) mm; lower glumes about 0.5 mm, awns 1-2(3) mm. 2n = 36.

In its native southern Africa, Melinis nerviglumis flowers from November to September [sic]. According to Anderson (1991), it is very similar to M. repens subsp. repens, differing from that species primarily in its strongly overlapping leaf sheaths and rolled leaf blades. The cultivar being marketed is 'Pink Crystal'.