Striga hermonthica (Delile) Benth.

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

Scrophulariaceae, S.A. Ghazanfar, F.N. Hepper & D. Philcox. Flora of Tropical East Africa. 2008

Type

Type: Egypt, Delile s.n. (MPU, holo.)

Morphology General Habit

Stiffly erect, dark green annual, much branched, 20–50 cm high.

Morphology Stem

Stems 4-angled with a groove on each face, scabrous

Morphology Leaves

Leaves opposite, linear to linear-lanceolate to lanceolate, 6–9 cm long, 1.1–1.5 cm wide, acute, margins entire, rather thick and leathery, both surfaces scabrous, margins with hispid hairs at regular intervals

Morphology Reproductive morphology Flowers

Flowers opposite or subopposite, 8–10 open at same time per inflorescence branch, variable in size; bracts almost as long as the calyx with prominent hispid hairs on the margins, tip curved away from stem; bracteoles half the length of the calyx

Morphology Reproductive morphology Flowers Calyx

Calyx 5-ribbed, 10–12 mm long, 2.5 mm wide, hispid on the ribs, intercostal portion whitish or pinkish and translucent, glabrous; lobes unequal, acuminate

Morphology Reproductive morphology Flowers Corolla

Corolla bright pink (rarely white); tube 10–20 mm long, bent just above calyx teeth, outside with very scattered hairs, glandular-pubescent; upper lobe emarginate, erect, lower lobes 10–13 mm long, 8–10 mm wide

Morphology Reproductive morphology Fruits

Capsule oblong, 12–15 mm long, 2–2.5 mm wide

Figures

Fig 38: 4–6, p 145

Ecology

Parasitic on the roots of maize ( Zea), millet ( Pennisetum), durra ( Sorghum), sugar ( Saccharum), finger millet ( Eleusine) and wild grasses; 750–1550 m

Conservation

Least Concern (LC); common and widespread

Note

The size of the corolla varies immensely: it is typically large and decorative but smalllflowered forms have been distinguished under the names S. senegalensis Benth. and S. gracillima Melchior, the latter having a slender inflorescence and the lower lip only 3 mm long. Although Melchior allied the latter species with S. warneckei Skan its affinities seem to lie with S. hermonthica owing to its broad bracts. Mohammed et al., op. cit. state that the corolla tube is never glandular-pubescent in S. hermonthica. I (S.A.G.) have examined many specimens of this taxon from the FTEA region and note the corolla tube to be more or less always glandular-pubescent, a character similar to that in S. apsera. S. hermonthica and S. aspera have been recorded to interbreed and it is possible that the hybrids have glandularpubescent corollas.

Distribution

Flora districts: U1 U2 U3 U4 K5 T1 Range: Serious pest in Sudan, also across West Africa to Senegal, and parts of eastern Africa, Egypt, also Madagascar

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

Morphology General Habit

Stiffly erect, dark green, much branched herb, 20–50 cm. tall.

Morphology Stem

Stem quadrangular with groove on each face, scabrous.

Morphology Leaves

Leaves rather thick, 6–9 x 1.1–1.5 cm., both surfaces scabrous, margins with hispid hairs at regular intervals.

Morphology Reproductive morphology Flowers

Flowers bright pink (rarely white), opposite or nearly so, 8-l6 open at same rime per inflorescence branch, variable in size, faint sweet fragrance in early morning.

Morphology Reproductive morphology Inflorescences Bracts

Bracts almost as long as calyx with prominent hispid hairs on margin, apex curved away from stem.

Morphology Reproductive morphology Inflorescences Bracteoles

Bracteole half length of calyx.

Morphology Reproductive morphology Flowers Calyx

Calyx 10–12 x 2.5 mm., intracostal portion whitish and translucent.

Morphology Reproductive morphology Flowers Corolla

Corolla tube 1–2 cm. long, bent just above calyx teeth, outside with very scattered hairs; upper lobe emarginate, erect, lower lobes 10–13 x 8–10 mm.

Morphology Reproductive morphology Fruits

Capsule 12–15 x 2–2.5 mm.