Lepironia mucronata Rich. [= Lepironia articulata (Retz.) Domin]

Medium-sized to tall perennials; rhizomes woody, creeping with thick roots. Culms scapose, erect, terete, with transverse septa. Basal leaves, reduced to a sheath, open in front, the margins overlapping, eligulate. Involucral bracts 1, large, subulate, cylindric, erect, culm-like. Inflorescence a single spike, pseudolateral, with many spirally arranged imbricate glume-like bracts; basal glume-like bracts empty, most subtending spicoids. Spicoids with 2 outer strongly keeled glumes and many non-keeled glumes, most subtending 1 stamen and a solitary apparently terminal female flower; rachilla thick and spongy. Florets unisexual; perianth absent. Stamens 1; anthers linear, apiculate; filaments highly accrescent. Style deeply 2-fid, long, slender; base not distinct, slightly thickened, persistent. Nutlets obovoid, dorsiventrally compressed, plano-convex, ± winged along the margins, beaked.

Lepironia occurs in Madagascar, and in tropical and subtropical Asia to the Western Pacific (POWO 2022). It grows in freshwater wetlands near sea level. In Madagascar, the single species of Lepironia, i.e. Lepironia articulata (Fig. 1), occurs along the east coast.

Figure 1. 

Lepironia articulata. A. Habit. B. Inflorescences. All photos taken in Vatomasina Vohipeno, Vohipeno District, Fitovinany Region by Botovao Auguste Ramiandrisoa, reproduced with permission from the photographer.

Hypolytrum latifolium Rich. ex Pers. [= Hypolytrum nemorum (Vahl) Spreng.]

Perennials, moderately robust to robust; rhizomatous or stoloniferous; rhizomes often woody, roots coarse. Culms trigonous or cylindrical, either laterally scapose and bearing reduced leaves at the base (cataphylls), or central with 1-several nodes and bearing well-developed leaves. Leaves eligulate, 3-ranked, sometimes pseudopetiolate; leaf sheath of basal leaves open adaxially; leaf sheath of cauline leaves tubular; blade linear to oblong-lanceolate or reduced (often in basal leaves), with 3, well developed principal veins, margin entire or many small teeth, gradually or abruptly narrowed at apex. Involucral bracts small, scale-like, or large and leaf-like, not sheathing, patent to reflexed. Inflorescence terminal, paniculate, corymbose or capitate, the ultimate branches subtending small clusters of spikes. Spicoids composed of 2(–3) floral bracts, each subtending 1 stamen (male flowers), often connate to varying degrees, the lower two followed by a bare pistil (female flower). Florets unisexual; perianth absent. Stamens 1; anthers oblong to linear, latrorsely dehiscent, without extended connective tip; filaments filiform, exceeding spicoid bract. Style 2-fid, exserted; base distinct or not, thickened or not, more or less persistent. Nutlets obovoid to ellipsoid, dorsiventrally biconvex, smooth, costate, wrinkled, tuberculate or spongious.

Hypolytrum is widely distributed in the tropics (POWO 2022). It grows in humid forests, on the edges of wetlands including mangroves, and in rocky areas near sea level. A single species of the genus, i.e. Hypolytrum nudicaule Juss. ex Cherm. (Fig. 2), occurs in eastern and northern Madagascar.

Figure 2. 

Hypolytrum nudicaule. A. Habit. B. Inflorescence. C. Plant base. All photos taken on Nosy Boraha Island by Justine Faure (https://www.inaturalist.org/observations/132556611), reproduced with permission from the photographer.

Coleochloa abyssinica (Hochst. ex A.Rich.) Gilly

Tufted or cushion-forming perennials; rhizomes extensively branched, infrequently forming a small caudex. Culms scapose or nearly so, compressed below, sometimes subcylindrical; erect or slightly wanting, basal part of culms covered by remains of old leaf sheaths. Leaves basal only, distichous; leaf sheath open on ventral side; ligule a line of fine hairs; contraligule not developed; blade flat or inrolled, deciduous. Involucral bracts more or less leaf-like; sheaths partly closed. Inflorescence terminal, paniculate, with few to many spikelet-like spikes; spikes bisexual, with numerous lateral spikelets subtended by small, densely spirally arranged glume-like bracts. Spikelet unisexual (male) or bisexual; lateral spikelets with an irregularly shaped prophyll. Glumes distichous, persistent, the larger 1–2 each subtending a flower, enclosed by the wings of the next glume. Basal spikelets with 1–2 male florets, apical spikelets mostly with 1 male and 1 female floret, more rarely completely female. Perianth surrounding the style base by 3 small, long fimbriate hypogynous scales, deciduous with the fruit. Stamens 2–3. Style 3-fid; base not distinct, tapering, persistent. Nutlets fusiform, trigonous, long beaked, surface smooth.

Coleochloa occurs in tropical and southern Africa and Madagascar (POWO 2022). It grows on inselbergs, between 600 to 2000 m in elevation. A single species of the genus, i.e. Coleochloa setifera (Ridl.) Gilly (Figs 3, 4A), occurs in northern and southeastern Madagascar and in the Central Highlands.

Figure 3. 

Coleochloa setifera. A. Habit, entire plant. B. Habit. C. Part of culm and leaf sheath. D. Leaf sheath opened to show ligule. E. Nutlet split open, seed enclosed. F. Seed. G. Nutlet, some bristles removed. H. Bristles detached from base of nutlet. I. Three fascicles of spikelets. J. Mature anther. K. Spikelet and bract, abaxial view. L. Spikelet, bract removed, adaxial view. M. Spikelet, glumes displaced, adaxial view. A–D, I–L from Browning 560; E–H from Pawek 13626a. Scale bars: A = 250 mm; B = 40 mm; C–M = 1 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Browning et al. (2020).

Figure 4. 

A. Coleochloa setifera. B. Costularia itremoensis. C. Eleocharis acutangula. All photos taken in the Itremo Massif Protected Area by Fitiavana Rasaminirina.

Cladium jamaicense Crantz [= Cladium mariscus subsp. jamaicense Kük.]

Robust perennials, up to several meters tall; rhizomatous, sometimes with swollen stolons. Culms with few-noded, internodes hollow. Leaves basal and cauline, V-shaped to flat, midribs and margins scabrid, eligulate. Involucral bracts leaf-like, sheathing. Inflorescence terminal or some lateral, paniculate; partial inflorescences anthelate. Spikelets numerous, short stalked or sessile. Glumes few to many, spirally arranged, persistent, increasing in length, with 2–3 upper glumes fertile. Lower floret mostly functionally male, upper florets bisexual. Perianth absent. Stamens 2–3. Style 2–3-fid, with a thickened persistent base. Nutlets ovoid, with a thick corky beak, surface smooth to wrinkled. Embryo small and poorly developed, broadly obovate in outline, with a basal, poorly developed root cap and without a leaf primordium.

Cladium is a cosmopolitan genus (POWO 2022). It grows in estuaries, freshwater wetlands, and lake margins up to 1500 m in elevation. In Madagascar, it is only known from the north where a single taxon, i.e. Cladium mariscus subsp. jamaicense (Fig. 5), has been recorded in the Sava region of Antsiranana province.

Figure 5. 

Cladium mariscus subsp. jamaicense. A. Habit. B. Inflorescence. C. Plant base, longitudinal section. D. Detail of leaf. E. Nutlet and upper unisexual floret with 2 filaments and rudimentary gynoecium. F. Spikelet. All from Ward 9082. Scale bars: A = 25 cm; B, C = 5 cm; D = 1 cm; E, F = 2 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Gordon-Gray (1995).

Diplacrum caricinum R.Br.

Small to medium-sized annuals or tufted, rarely stoloniferous perennials. Culms scapose or leafy, often short. Leaves eligulate; blade linear or lanceolate, alternate, simple, often reddish purple abaxially. Primary bracts leaf-like, sheathing. Inflorescence paniculate or capitate; partial inflorescences anthelate or capitately contracted. Spikelets many, lateral spikelets usually male, terminal spikelets usually female. Glumes male spikelets with few distichous, persistent glumes, each subtending a male floret; female spikelet with 2 distichous, persistent glumes, sometimes deciduous with the fruit, surrounding a pseudo-terminal female floret. Florets unisexual. Bristles absent. Stamens 1; anthers sightly oblongs. Pistil seated on a basal trilobed disc, lobes opposite the 3 main ribs; style 3-fid ; base not distinct, not thickened, deciduous. Nutlets subglobose to ovoid, inconspicuously 3-ribbed, beak short, surface smooth, ribbed, or reticulate.

Diplacrum is widely distributed in the tropics and tubtropics (POWO 2022). It grows in damp soils and freshwater wetlands including rice fields, usually near sea level. A single species of Diplacrum, i.e. Diplacrum africanum (Benth.) C.B.Clarke (Fig. 6), is known from northwestern and east central Madagascar, and from the southeast along the mountain range.

Figure 6. 

Diplacrum africanum. A, C. Habit. B Leaf. D. Inflorescence. E. Spikelets, male and female with bract and prophyll. F. Prophyll. G–H. Female spikelet, with and without nutlet. I–J. Nutlet, lateral and basal view. B–D, G–J from Robinson 2851; A, E, F from Bidgood et al. 3967. Scale bars: A, B = 25 mm; C = 10 mm; D–H = 1 mm; I, J = 0.5 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Browning et al. (2020).

Scleria flagellum-nigrorum P.J.Bergius

Habit variable, from tiny annuals with fibrous roots to perennial climbers more than 10 meters tall; stoloniferous rhizome or tubers; aerial adventitious roots at stem nodes (adaptation to flooded habitats). Culms trigonous or triquetrous, noded bearing leaves often without ligules, sometimes with a contraligule. Leaves alternate, tristichously arranged, often persistent at the base, and finely serrate at least along the distal third of the margins, rarely smooth: sometimes abruptly narrowed down or pseudopraemorse; sheaths sometimes winged, usually topped by a contraligule, opposite to the blade. Inflorescence bracts leaf-like and sheathing, setaceous, or glume-like; spikelet bract usually setaceous, rarely glume-like. Inflorescence variable, usually paniculate, but often with contracted partial inflorescences. Spikelets bearing flowers of one or both sexes, the bisexual ones with one basal female and one to few male flowers above; female spikelet similar but upper part reduced to 1–2 empty scales or wanting; male spikelet lacking basal female flower and with more male flowers. Glumes in androgynous or bisexual spikelets the lower part is female with distichously arranged glumes (a few may be empty), upper part male with few to many spirally arranged glumes. Florets always unisexual, enclosed by at least three glumes. Bristles absent. Stamens 1–3, anthers often linear, more or less apiculate. Style 3-fid; ovary surrounded at the base by a variously shaped (sometimes reduced) lobed hypogynium, which is shed with the fruit. Nutlets globose to ovoid, variously sculptured and ornamented, usually white, sometimes beaked, subtended by a cupule, frequently surrounded by a hypogynium.

Scleria is widely distributed in the tropics and subtropics up to North America (POWO 2022). It grows in seasonally damp or permanently wet habitats, woodland, forests stream sides, and grasslands (Browning and Goetghebeur 2017). Scleria occurs throughout Madagascar. The 25 previously known species, including e.g. Scleria bulbifera Hochst. ex A.Rich. (Fig. 7) and Scleria distans Poir. (Fig. 8A), were recently monographed (Díaz et al. 2019), and a new species has been recently discovered from northern Madagascar (Larridon et al. unpubl. data).

Figure 7. 

Scleria bulbifera. A. Habit showing rhizome. B. Junction of lamina and sheath. C. Androgynous spikelet with lower prophyll and one glume removed; remainder displaced to show lower female floret and upper male florets. D. Glomerule of three spikelets. E. Nutlet. A–D from Hilliard & Burtt 13394; E from Hilliard & Burtt 18036. Scale bars: A = 40 mm; B–E = 2 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Gordon-Gray (1995).

Figure 8. 

A. Scleria distans. B. Bulbostylis itremoensis. C. Fuirena pubescens (pale green) and Schoenoplectiella corymbosa (dark green). All photos by Fitiavana Rasaminirina.

Carpha alpina R.Br.

Perennials, small to medium-sized (rarely tall), tufted, mat-forming; rhizomatous or rarely stoloniferous. Culms erected, trigonous to more or less cylindrical, scapose or with a few nodes. Leaves basal and cauline, eligulate. Lower primary bracts more or less leaf-like, sheathing. Inflorescence open to condensed paniculate with (sub)capitate partial; inflorescences with few to many spikelets. Spikelets with 3–6 distichous, persistent glumes of increasing length. Lower glumes empty, larger 1–2(–3) glume(s) each subtending a floret, enclosed by the wings of the next glume. Floret bisexual, sometimes upper or lower floret male. Bristles 6, ciliate to partly fimbriate or plumose, shorter than to much longer than the fruit, deciduous with the fruit. Stamens 2–3, anthers conspicuously greenish yellow. Style 3-fid, base not distinct, slightly thickened, persistent, often scabrid. Nutlets narrowly (ob)ovoid to oblong, trigonous, often with a long beak, surface smooth or finely reticulate.

Carpha occurs from Uganda to South Africa, Western Indian Ocean, South Japan, New Guinea to New Zealand and South America. It grows along streams, on marshy ground, and on rocks, from 1800 to 2500 m in elevation. In Madagascar, a single species of Carpha, i.e. Carpha perrieri Cherm., is known from Fianarantsoa province Matsiatra Ambony region and Toliara provinces Anosy region.

Rhynchospora alba (L.) Vahl

Usually small to medium-sized perennials, rarely annuals; rhizomatous or with a poorly developed root system. Culms scapose or with 1-many nodes, rounded to trigonous. Leaves radical or radical and cauline; sheaths closed, ligule minute or absent. Involucral bracts leaf-like or reduced. Inflorescence very variable, paniculate, corymbose, anthelate or capitate, rarely pseudolateral. Glumes spirally arranged (rarely distichous), of increasing length to subequal, larger (1–)2-few glume(s) subtending a floret, enclosed by the wings of the next glume. Florets bisexual, the lowest few sterile and/or upper staminate (variable with species). Perianth bristles usually 3–6, or absent. Stamens (1–2–)3, inconspicuous. Style 2-fid, with base persistent (tubercle). Nutlets usually lenticular to globose. Embryo top-shaped in frontal view, root cap developed in a (sub)basal position, and first leaf primordium developed in a lateral position (Carex-type embryo).

Rhynchospora is a cosmopolitan genus (POWO 2022). It grows in seasonally wet to permanently flooded grassland, laterite outcrops, lake shores, stream sides, swamps, rice fields (Browning and Goetghebeur 2017). Rhynchospora occurs throughout Madagascar; ten species are known including e.g. Rhynchospora holoschoenoides (Rich.) Herter (Fig. 11) and Rhynchospora angolensis Turrill (Fig. 12A).

Figure 11. 

Rhynchospora holoschoenoides. A–B. Habit. C. Leaf sheath. D. Leaf apex. E. Inflorescence. F. Head of spikelets. G–H. Spikelet, complete and opened to show florets. I. Glume, lateral view. J. Nutlet. A–D from Robinson 6123; E, G, I from Robinson 1048; F from Robinson 1456; J from Renvoize 5598. Scale bars: A = 250 mm; B, E = 40 mm; C, F = 5 mm; G–I = 2 mm; D, J = 1 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Browning et al. (2020).

Carex hirta L.

Generally perennials, rarely annuals, caespitose or rhizomatous, sometimes forming a compact tussock. Culms central or lateral, mostly scapose, rarely with nodes, simple, smooth or scabrid. Leaves generally present, glabrous or rarely hairy, sheath often surrounding culm, ligule or sometimes contraligule present at the junction of the sheath and the blade. Primary bracts leaf-like or not, sheathing or not. Partial inflorescences spike-like, unisexual or bisexual, with few to many spirally arranged bracts (or glumes), either subtending a female spikelet or a male floret. Inflorescence terminal, rarely pseudolateral, paniculate, often partly or completely contracted, rarely corymbose or anthelate with few to numerous spikes, less frequently reduced to a single spike, cladoprophylls sometimes swollen at the base, utriculiform and subtending a female floret; inflorescence mostly bisexual, rarely unisexual or florets dioecious. Spikes male, female, or bisexual, and then mostly male florets apically, rarely basally, or intermingled; female spikelet reduced to the rachilla and a utriculiform, flower-bearing prophyll, completely enclosing the rachilla. Glumes 0 or 1. Floret unisexual; staminate flowers without scales; pistillate flowers with 1 scale with fused margins (perigynium) enclosing flower, open only at apex. Bristles absent. Stamens 1–3, filaments distinct, anthers linear. Style 2–3-fid, exserted, base not distinct, rarely thickened, persistent. Nutlets often obovoid, trigonous, or dorsiventrally compressed, sometimes remarkably malformed.

Carex is a cosmopolitan genus (POWO 2022). It grows in humid forest, wet grassland, in freshwater wetlands, on sand or rocks, usually at higher elevation. Carex (Fig. 12B) occurs throughout Madagascar; 30 species are known.

Figure 12. 

A. Rhynchospora angolensis; photo taken in the Itremo Massif Protected Area by Fitiavana. Rasaminirina. B. Carex sp.; photo taken in the Mantadia National Park by Vida. Svahnstrom.

Scirpus palustris L. [= Eleocharis palustris (L.) Roem. & Schult.]

Very small to medium-sized tufted annuals or large rhizomatous, stoloniferous perennials; rhizome often strong, horizontal, often producing stolons. Culms scapose, 3–4 angular, ridged or terete, occasionally septate, ancipitous or bulbously thickened at base. Leaves reduced to inconspicuous basal sheaths, rarely with a short blade, eligulate. Primary bracts absent, rarely proximal scale of spikelet resembling short bract. Inflorescence solitary terminal spikelet, usually quite short and ebracteate. Spikelets with 2–many spirally arranged, rarely subdistichous, deciduous imbricate glumes, each subtending a floret. Lowermost glume often empty or with a vegetative bud, rarely flower-bearing. Floret bisexual. Bristles barbellate, (0–)3–6(–10), or reduced to a narrow rim underlying nutlet, shorter or longer than nutlet and shed with it. Stamens 1–3; anthers linear. Style 2–3-fid, upper portion deciduous, base enlarged persistent as a conical or flattened appendage on nutlet. Nutlets obovoid, lenticular or trigonous, beaked smooth or variously ornamented with pits in longitudinal rows.

Eleocharis is a cosmopolitan genus (POWO 2022). It grows in forest, wet grasslands, freshwater wetlands, along rivers, lake margins, and rice fields, and in rocky areas. Eleocharis occurs throughout Madagascar; 12 species are known including e.g. Eleocharis acutangula (Roxb.) Schult. (Fig. 4C) and Eleocharis dulcis (Burm.f.) Trin. ex Hensch. (Fig. 13).

Figure 13. 

Eleocharis dulcis. A. Habit (× 1/3). B. Inflorescence (× 1.5). C. Floret (× 10). D. Nutlet (× 12). A from Kirika et al. NMK 778; B from Vesey-Filtzgerald 401; C from Milne-Redhead & Taylor 9164; D from Faden et al. 96/468. Drawn by Juliet Beentje, reproduced with permission from the artist, originally published in Hoenselaar et al. (2010).

Scirpus capillaris L. [= Bulbostylis capillaris (L.) Kunth ex C.B.Clarke]

Small to medium-sized annuals or tufted perennials, rarely with an elongated rhizome, rarely forming a caudex; rhizome woody, variable, usually compact with swollen confluent shoot bases, occasionally elongate in uniseriate or multiseriate rows, less often of uniform thickness throughout. Culms scapose, terete, ridged and furrowed, glabrous to pilose or densely velutinous apically. Leaves eligulate (rarely ligulate), but with two lateral tufts of long white hairs at the sheath mouth, rarely reduced to a sheath. Primary bracts short, not sheathing, rarely the lowermost bract leaf-like and erect. Inflorescence terminal, rarely pseudolateral, anthelate or capitate. Spikelets few to many, or reduced to a single spikelet, often with many densely spirally arranged (rarely distichous), deciduous glumes, each subtending a floret. Florets bisexual. Perianth bristles absent. Stamens 1–3, anthers generally oblongs or linear, often acute, rarely setiferous. Style (2–)3-fid, base distinct, thickened, persistent, rarely only slightly thickened or deciduous. Nutlets obovoid to obpyriform, rounded trigonous, rarely dorsiventrally lenticular, surface with various ornamentations, rarely smooth.

Bulbostylis is widely distributed in the tropics and subtropics to Central Asia (POWO 2022). It grows in grasslands and woodlands, along roadsides and among rocks. In Madagascar, Bulbostylis is known from the northwest, the Central Highlands, and the southwest. This genus is currently being monographed (Rasaminirina et al. unpubl. data), and ca 25 species are currently known to occur in Madagascar including e.g. Bulbostylis itremoensis Lye ex Rasam. (Fig. 8B) and Bulbostylis hispidula (Vahl) R.W.Haines (Fig. 14).

Figure 14. 

Bulbostylis hispidula. A. Habit. B. Glume. C. Nutlet. D. Spikelet. E. Mouth of leaf sheath. F. Young nutlet with style. All from Ward 610. Scale bars: A = 40 mm; B, C = 5 mm; D–F = 0.5 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Gordon-Gray (1995).

Trichoschoenus bosseri J.Raynal

Small to medium-sized tufted perennials; thick roots. Culms scapose, densely hairy, flattened, tufted. Leaves reduced to a sheath, leaf sheath of increasing length, blade sometime present as a short mucro, eligulate. Primary bracts mostly as long as or shorter than spikelet, not sheathing. Inflorescence capitate. Spikelets many. Glumes 3, distichous, deciduous, of increasing length, the second subtending a floret, enclosed by the wings of the next. Florets bisexual. Perianth bristles absent. Stamens 3. Style deeply 3-fid, base more or less distinct, thickened, persistent. Nutlets obovoid, trigonous, with a thick short beak, surface minutely reticulate.

Trichoschoenus is the only endemic genus of Cyperaceae in Madagascar. Its only species Trichoschoenus bosseri (see Browning and Goetghebeur 2017: 85) has only been collected near Ihosy in the Central Highlands (Raynal 1968). It grows in dry sandy soil, in open woodland (Browning and Goetghebeur 2017) between 500 to 1000 m in elevation (Catalogue of the Vascular Plants of Madagascar 2023).

Actinoschoenus filiformis (Thwaites) Benth. [= Actinoschoenus aphyllus (Vahl) Larridon]

Small to medium-sized, tufted, shortly rhizomatous or stoloniferous perennials. Culms scapose, smooth, tufted, more or less 4-angular, bases covered by closed leaf sheaths. Leaves ligulate if present, blade very short, almost reduced to a sheath. Primary bracts small, not very conspicuous not sheathing. Inflorescence terminal, capitate. Spikelets 2 or many. Glumes 4–7 distichous, deciduous glumes, of increasing length; rachilla internodes short, somewhat elongated between the florets. Floret(s) 1(–2), subtended by the penultimate larger glume, enclosed by the wings of the next glume, bisexual. Perianth bristles absent. Stamens 3. Style deeply 3-fid, style base distinct, thickened, deciduous. Nutlets obovoid, trigonous, more or less 3-ribbed, surface smooth to slightly tuberculate.

Actinoschoenus occurs from West-Central Tropical Africa to Zambia, Western Indian Ocean, Sri Lanka to southern China and Australia (POWO 2022). It grows in open woodland on dry sandy areas (Browning and Goetghebeur 2017), wetlands, swamps, sands and wet rocks, water’s edge, forest, to 800 m elevation (Chermezon 1937). A single species of Actinoschoenus, i.e. Actinoschoenus aphyllus (Vahl) Larridon (Fig. 15), occurs throughout Madagascar.

Figure 15. 

Actinoschoenus aphyllus. All photos taken in Andrainjato, Taolagnaro District, Anosy Region by Andriambolantsoa Rasolohery (https://www.inaturalist.org/observations/145409565), reproduced with permission from the photographer.

Cyperus monostachyos L. [= Abildgaardia ovata (Burm.f.) Kral]

Small to medium-sized annuals or tufted perennials; short woody rhizome. Culms scapose, rounded, generally glabrescent, rarely scabrid. Leaves eligulate, sometimes reduced to a sheath, basal polystichous, sheaths distally open, loose, ribbed; blades mostly filiform, compressed or lunate to semicircular in cross section, margins strongly involute. Primary bracts short, not sheathing, inconspicuous. Inflorescence terminal, depauperate anthelate or capitate. Spikelets few or reduced to one single spikelet. Glumes many densely (spiro) distichous, deciduous, each subtending a floret. Floret bisexual, protandrous. Perianth bristles absent. Stamens 2–3. Style deeply 3-fid, base distinct, thickened, deciduous. Nutlets mostly obovoid, stipitate, rounded trigonous, rarely winged, surface often tuberculate.

Abildgaardia is widely distributed in the tropics and subtropics (POWO 2022). It grows in grasslands, woodlands, freshwater wetlands, and brackish marshes. Abildgaardia occurs throughout Madagascar; two species are known including e.g. Abildgaardia triflora (L.) Abeyw. (Fig. 16).

Figure 16. 

Abildgaardia triflora. A. Habit. B. Two leaf bases. C. Leaf apex. D. Spikelet. E. Rachilla. F, G. Glume, complete and upper abscised part. H. Young floret. I. Style and branches. J. Nutlet with filaments. All from Robinson 2038. Scale bars: A = 40 mm; B, C, H–J = 2 mm; D–G = 5 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Browning et al. (2020).

Scirpus dichotomus L. [= Fimbristylis dichotoma (L.) Vahl]

Annuals tufted or perennials with rhizomes. Culms scapose or subscapose, terete or 3–4–5-angular or ancipitous, variously pubescent to glabrous. Leaves spirally or distichously arranged, or reduced to a sheath, ligulate or eligulate; blade linear, filiform, or rarely ensiform, usually dorsiventrally compressed and canaliculate, often adaxially cellular-reticulate. Primary bracts short, not sheathing. Inflorescence variable usually capitate or anthelate. Spikelets few to numerous, or reduced to a single spikelet, mostly cylindric. Glumes usually spirally arranged, rarely distichous, deciduous, each subtending a bisexual floret. Perianth bristles absent. Stamens 1–3. Style 2–3-fid, often flattened with fimbriate margins when 2-fid; base distinct, thickened, deciduous. Nutlets obovoid, trigonous or biconvex and often variously ornamented, trigonous when style 3-fid, lenticular when style 2-fid, smooth, tuberculate or longitudinally ribbed, not transversely wrinkled.

Fimbristylis is a cosmopolitan genus (POWO 2022). It grows on seasonally wet or damp sandy soils in grassland, woodland, riverbeds, and rice fields, also on rocks in shallow soil (Browning and Goetghebeur 2017). Fimbristylis occurs throughout Madagascar; 17 species are known including e.g. Fimbristylis dichotoma (Fig. 17).

Figure 17. 

Fimbristylis dichotoma. A, B. Habit. C. Leaf sheath apex. D. Leaf apex. E. Spikelet. F, G. Glume, abaxial and lateral view. H. Floret. I. Nutlet. All from Brummitt 9546. Scale bars: A = 250 mm; B = 40 mm; C, E = 5 mm; D = 2 mm; F–I = 1 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Browning et al. (2020).

Bolboschoenus maritimus (L.) Palla

Perennials with long rhizomes often forming hard ovoid tubers at tips. Culms many-noded, sharply trigonous, thickened at base. Leaves basal and cauline, eligulate; blade often reduced in lower leaves. Involucral bracts leaf-like, patent, lowermost often suberect. Inflorescence terminal (in reduced inflorescences, bract may be erect, but clearly leaf-like), a (compound) corymb-like anthela or capitate with 1-many spikelets. Spikelets with many spirally arranged, deciduous glumes, each subtending a flower. Glumes puberulent, the apex entire to emarginate or deeply 2-fid, awned or mucronate. Floret bisexual. Perianth present, formed by 3–6 parts, shorter to longer than the nutlet, bristle-like, deciduous with fruit. Stamens 3. Style 2–3-fid; base persistent, barely thickened. Nutlets obovate, dorsiventrally lenticular or trigonous. Pericarp with the three highly differentiated layers, exocarp cells often enlarged and hollow; surface smooth, epidermal cells roughly isodiametric. Embryo fungiform with three primordial leaves.

Bolboschoenus is a cosmopolitan genus (POWO 2022). It grows in saline, brackish, or freshwater wetlands. In Madagascar, Bolboschoenus is known from the north and west, occurring in the Diana Region of Antsiranana province, Boeny region of Mahajanga province, and Atsimo Andrefana region of Toliara province. Only a single species occurs in Madagascar, i.e. Bolboschoenus glaucus (Lam.) S.G.Sm. (Fig. 18).

Figure 18. 

Bolboschoenus glaucus. A. Habit. B. Inflorescence and leaves. C. Leaf sheath apex. D. Spikelet. E. Anther. F. Ovary, style and branches. G, H. Glume, adaxial and abaxial surface. I. Glume apex. J. Nutlet, abaxial view. K, L. nutlet sections. All from van Rensburg 2404. Scale bars: A = 250 mm; B = 10 mm; C = 40 mm; D–K = 2 mm. Abbreviations: ex = exocarp, m = mesocarp, en = endocarp. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Browning et al. (2020).

Fuirena umbellata Rottb.

Annuals or rhizomatous perennials. Culms many-noded, rarely scapose, 3–5-sided, sometimes thickened at base. Leaves usually well developed, basal and cauline, ligule tubular, membranous, with blade often reduced in lower leaves (rarely all leaf blades reduced). Involucral bracts leaf-like, usually sheathing, lowermost bract sometimes erect. Inflorescence terminal (in reduced inflorescences, bract may be erect, but clearly leaf-like), paniculate to capitate with few to many spikelets. Glumes many, spirally arranged or rarely pentastichously arranged, deciduous, each subtending a flower, often pubescent, the apex entire and mucronate to awned. Floret bisexual. Perianth present, as long or shorter than nutlet, formed by 3 parts, or when 6 in 2 whorls, the inner parts scale-like, the outer parts bristle-like, rarely all parts reduced or absent or only 1 scale developed, deciduous with the fruit. Stamens 1–3. Style 3-fid, base persistent, barely thickened, if at all. Nutlets obovate, triquetrous to trigonous, frequently stipitate, smooth or variously ornamented. Embryo turbinate to weakly fungiform with a horizontally broadened scutellum, first leaf primordium not strongly outgrown, the second leaf primordium either absent or poorly developed.

Fuirena is a cosmopolitan genus (POWO 2022). It grows in seasonally wet grasslands, freshwater wetlands, on sand or in rocky areas. Fuirena occurs throughout Madagascar; seven species are known including e.g. Fuirena pubescens (Poir.) Kunth (Figs 8C, 19).

Figure 19. 

Fuirena pubescens. A. Nutlet. B. Habit. C. Leaf sheath apex. D. Inflorescence. E. Glume lateral view. F. Floret. A–C from Taylor 36; D–F from Browning 165. Scale bars: A = 40 mm; B, C = 5 mm; D–F = 1 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Gordon-Gray (1995).

Schoenoplectus lacustris (L.) Palla

Perennials with long rhizomes sometimes ending in tubers at tips. Culms scapose, trigonous to terete, thickened at base. Leaves usually reduced to a sheath, sometimes developing a ligulate blade, but rarely well developed. Involucral bracts often large, erect, stem-like, rarely leaf-like, and patent to reflexed. Inflorescence pseudolateral, rarely clearly terminal, corymb-like anthela or capitate. Spikelet 1 or few. Glumes many, spirally arranged, deciduous, each subtending a flower; puberulent to glabrous, the margins often ciliate or laciniate distally, apex entire to emarginate or deeply 2-fid, awned or mucronate. Floret bisexual. Perianth present, formed by (5–)6 parts, smooth to retorsely scabrid, bristle-like or sometimes plumose, longer or shorter than nutlet, deciduous with fruit. Stamens 2–3. Style 2–3-fid, base not thickened, persistent. Nutlets smooth, obovate, trigonous, or dorsiventrally lenticular, yellow to dark brown when mature; fruit epidermal cells isodiametric to narrowly oblong. Embryo fungiform, scutellum turbinate to rhomboid in shape, root cap lateral, first well developed and second embryonic leaves basal.

Schoenoplectus is a cosmopolitan genus (POWO 2022). It grows in freshwater wetlands, along stream banks, wet grasslands, and rocky areas. In Madagascar, only two species of Schoenoplectus occur including e.g. Schoenoplectus subulatus (Vahl) Lye (Haines and Lye 1983: 54).

Scirpus articulatus L. [= Schoenoplectiella articulata (L.) Lye]

Annuals or perennials, tufted or with firm, short to creeping rhizomes. Culms nodeless and scapose or 1(–3)-noded above the base, trigonous, terete or rarely 7-sided. Leaves reduced to a mucronate sheath, rarely with well-developed blades, ligulate or eligulate. Involucral bracts culm-like, erect, or patent while fruiting, rarely short, rigid, and sheathing, but then appearing as a continuation of the stem. Inflorescence pseudolateral, rarely appearing terminal, a corymb-like anthela or capitate with 1-many spikelets, rarely compound-paniculate with 1-many spikelets, with a conspicuously sinuous main axis. Glumes many, spirally arranged, deciduous or persistent, each subtending a flower; scale apex entire to apiculate. Floret bisexual, rarely polygamodoecious. Perianth bristles present or absent, formed by 0–10 parts, smooth or retrorsely scabrid, bristle-like, as long as or longer than the nutlet, deciduous with the fruit. Stamens 2–3, rarely vestigial in female flowers. Style 2–3-fid, base undifferentiated, rarely distinct and somewhat thickened, persistent. Nutlets smooth or transversely rugose to distinctly ridged, obovate, trigonous to planoconvex or biconvex, dark nearing black when mature, sometimes brown.

Schoenoplectiella is a cosmopolitan genus (POWO 2022). It grows in freshwater wetlands, along stream banks, wet grasslands, and rocky areas. Schoenoplectiella is known from all parts of Madagascar; 13 species are known including e.g. Schoenoplectiella corymbosa (Roth ex Roem. & Schult.) J.R.Starr & Jim.Mejías (Figs 8C, 20).

Figure 20. 

Schoenoplectiella corymbosa. A. Partial habit (× 2/3). B. Inflorescence (× 2/3). C. Spikelet (× 6). D. Glume (× 10). E. Young floret (× 10). F. Floret (× 10). G. Nutlet (× 20). A from Richards 6616; B, G from Greenway & Kanuri 12546; C–F from Grimshaw 93. Drawn by Juliet Beentje, reproduced with permission from the artist, originally published in Hoenselaar et al. (2010).