Striga Lour.

Scrophulariaceae, D. Philcox. Flora Zambesiaca 8:2. 1990

Habit

Annual, rarely perennial, hirsute or scabrous root-parasitic herbs.

Roots

Root system greatly condensed, adventitious roots arising from subterranean scales, these fine roots terminated by small (1–2 mm. in diam.) haustoria, in some species a large (to 5 cm.) primary haustorium present.

Stem

Stems stiffly erect, green or grey, usually square in transverse section, of ten ridged.

Leaves

Leaves opposite or nearly so, sessile or subsessile, reduced to small scales near the base of the stem in most species.

Inflorescences

Inflorescence a spike, flowers in axils of leaves (bracts) or in dense heads.

Bracteoles

Bracts leaf-like or reduced, bracteoles 2.

Calyx

Calyx tubular, 5-lobed or with 5 (rarely 4) teeth, in some species intracostal veins occur.

Corolla

Orifice of tube small, less than 1 mm. in diam. with hairs abundant at orifice. Corolla with a narrow tube and expanded bilabiate limb. Upper lobes fused, erect, lower lobes 3, spreading.

Stamens

Stamens 4, didynamous, inserted in the tube below the orifice.

Anthers

Anthers unilocular, basifixed on short filaments.

Pollen

Pollen sparse, of ten sticky.

Pistil

Pistil tubular with numerous minute ovules.

Style

Style terete, elongate, stigma bifid.

Nectaries

Nectary present at base of ovary.

Fruits

Dehiscence loculicidal. Capsule cylindric or subovoid, style usually persistent.

Seeds

Embryo small. Seeds minute (“dust seeds”) with prominent encircling ridges. Seedlings achlorophyllous, squamate. Germination hypogeal and cryptocotylar.