Ammannia linearis (Hiern) S.A.Graham & Gandhi

Lythraceae, A. Fernandes. Flora Zambesiaca 4. 1978

Morphology General Habit

Annual, erect, glabrous herb, up to 1 m. high.

Morphology Stem

Stem usually simple and subterete below, 4-gonous and branched upwards.

Morphology Leaves

Leaves 20–80 x 3–10 mm., decussate, linear, acute at the apex, obtuse, acute or cuneate at the base, rigid, 1-nerved.

Morphology Reproductive morphology Inflorescences

Dichasia capituliform, large, subglobose, at the ends of stems and branches, very dense, many-flowered and sessile, surrounded at base by several imbricate bracteoles, the bracteoles reniform, acuminate, venose.

Morphology Reproductive morphology Flowers

Flowers 4–6-merous, dimorphic-heterostylous, in subsessile clusters (the flowers also subsessile in the clusters), surrounded by oblong bracteoles expanded upwards and shortly acuminate at the apex. Short-styled flowers: filaments of long stamens 7 mm. long, exceeding the stigma by 2·5 mm.; filaments of short stamens 5·5 mm., exceeding the stigma by 1 mm.; style c. 4·2 mm. long. Long-styled flowers: filaments of long stamens 6 mm. long, exceeding the appendages by 2 mm.; filaments of short stamens 4 mm. long, scarcely attaining the apex of the appendages; style 7·5 mm. long.

Morphology Reproductive morphology Flowers Calyx

Calyx-tube 3–4 mm. long, narrowly campanulate, membranous, 8–12-nerved; lobes c. 0·5 mm. high, debate, acute; appendages erect or arching, much longer than the lobes (c. 2 mm.), ciliate at the top.

Morphology Reproductive morphology Flowers Corolla

Petals c. 4·5 mm. long, purple, narrowly obovate, caducous.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens as many as the calyx-lobes, inserted near the base of the calyx-tube (the epipetalous on a higher level).

Short-styled

Short-styled flowers: filaments of long stamens 7 mm. long, exceeding the stigma by 2·5 mm.; filaments of short stamens 5·5 mm., exceeding the stigma by 1 mm.; style c. 4·2 mm. long.

Long-styled

Long-styled flowers: filaments of long stamens 6 mm. long, exceeding the appendages by 2 mm.; filaments of short stamens 4 mm. long, scarcely attaining the apex of the appendages; style 7·5 mm. long.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 1·7 mm. long, ellipsoid, 2-locular.

Morphology Reproductive morphology Fruits

Capsule and seeds not seen.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/179424/1578120

Conservation

EN - endangered

Lythraceae, B. Verdcourt. Flora of Tropical East Africa. 1984

Morphology General Habit

Erect annual glabrous herb, 0.25–1 m. tall; stems 4-angled, simple beneath, sparsely to ± much-branched in upper quarter, somewhat woody at base.

Morphology Leaves

Leaves rigid, decussate, linear to linear-lanceolate or very narrowly elliptic, 2–8 cm. long, 0.3–1 cm. wide, acute at the apex, acute to obtuse at the base, 1-nerved.

Morphology Reproductive morphology Flowers

Flowers 4–6-merous, heterostylous, subsessile, arranged in subsessile clusters aggregrated into terminal subglobose inflorescences up to 1.5 cm. long, 1.8 cm. wide, surrounded at the base by several reniform imbricate venose acuminate bracts ± 9 mm. wide; bracteoles oblong-spathulate, 5–6 mm. long, widened at the apex, acuminate. Long-styled flowers:longer filaments 6 mm. long, shorter 4 mm. long; style 7.5 mm. long. Short-styled flowers:longer filaments 7 mm. long, shorter filaments 5.5 mm. long, overtopping stigma by 2.5 and 1 mm. respectively; style 4.2 mm. long.

Morphology Reproductive morphology Flowers Calyx

Calyx-tube narrowly campanulate, 3–4 mm. long, thin, 8–12-nerved; lobes triangular, 0.5 mm. long, acute, the alternating appendages erect or curved, narrow, ± 2 mm. long, ciliate above the middle.

Morphology Reproductive morphology Flowers Corolla

Petals purple or mauve, narrowly obovate, ± 4.5 mm. long, deciduous.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens as many as the calyx-lobes.

Short-styled

Short-styled flowers:longer filaments 7 mm. long, shorter filaments 5.5 mm. long, overtopping stigma by 2.5 and 1 mm. respectively; style 4.2 mm. long.

Long-styled

Long-styled flowers:longer filaments 6 mm. long, shorter 4 mm. long; style 7.5 mm. long.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary ellipsoid, 1.7 mm. long, 2-locular.

Morphology Reproductive morphology Fruits

Immature capsule ellipsoid-globose, 3 mm. long.

Figures

Fig. 8/22–29, p. 25,

Habitat

Seasonally waterlogged grassland (e.g. Hyparrhenia rufa and Oryza longistaminata) on blackish sandy soil with Rhynchospora Candida and other sedges; 30–35 m.

Distribution

T6 T8