Petals obovate or spathulate, 6–10 mm. long, 4–6 mm. wide, obtuse or refuse, white or purple (rarely pale purple) with conspicuous red veins.
Stamens: filaments narrowly lanceolate, 3.5–6 mm. long, cream, hispid along the margins towards the base; anthers 0.7–1.3 mm. long, 0.5–0.7 mm. wide, brown.
Ovary pubescent; stigmas 1–3 mm. long, purple to dark red.
Mericarps smooth, pilose; mature rostrum 12–20 mm. long, ± 2 mm. wide, pubescent.
Inflorescence usually 2-flowered, the flowers rarely solitary by reduction; peduncles 3–10 cm. long, grooved or terete, pubescent or pilose; pedicels 1–4 cm. long; bracts lanceolate, 3–5 mm. long, hyaline along the edges.
Sepals broadly lanceolate, 6–10 mm. long, 2–3 mm. wide, cuspidate or mucronate, 3–nerved, pilose to pubescent on the outer surface, glabrous inside.
Leaves usually opposite but sometimes in basal rosettes especially the radical ones, occasionally pinkish-red on the lower surface; lamina 5-lobed, divided to three-quarters of the radius; lobes 3–10 mm. wide at the base, broadly elliptic to rhombic in outline, pinnatifid or incised, stiffly pubescent or pilose on both surfaces especially along the veins; petiole (l–)4–26 cm. long, pilose; stipules entire, ovate-lanceolate, 5–12 mm. long, 3–5 mm. wide, acute to acuminate, membranous, pilose or pubescent.
Perennial diffusely branched or ascending, occasionally tufted, herb up to 9 dm. long; stems somewhat woody, stoloniferous, creeping and scrambling, longitudinally grooved, pilose or pubescent with short reflexed appressedhairs at least above, often glabrescent below; internodes (l–)3–25 cm. long, 0.8–2.5 mm. thick.
Seeds ovoid, 1.9–2.4 mm. long, 1–1.5 mm. wide, glabrous; testa covered with very shallowly reticulate pattern, dark grey to somewhat brown.
Leaf-lamina 5-lobed, divided to 3/4 or more; lobes 3–10 mm. across at base, broadly elliptic to rhombic in outline, pinnatifid to pinnatilobed, stiffly pubescent or pilose on both the upper and lower surfaces; petiole 1–16 cm. long, pilose; stipules 5–12 × 3–5 mm., entire, ovate-lanceolate, acute to acuminate, membranous, pilose or pubescent.
Flowers in 2-flowered inflorescences, or, rarely, 1-flowered by reduction; peduncle 3–10 cm. long, furrowed or terete, pubescent or pilose; pedicels 1–4 cm. long, furrowed or terete, pubescent or pilose; bracts 3–5 mm., lanceolate, hyaline at the edge.
Sepals 7–10 × 2–3 mm., broadly lanceolate, cuspidate or mucronate, 3-nerved, pilose and pubescent.
Petals about 10 × 5–7 mm., obovate, refuse at the apex, white or pink (rarely pale purple) with conspicuous red veins.
Stamens 10, filaments about 3 mm. long, narrowly lanceolate.
Cocci smooth, pilose; mature rostrum 12–20 × 2 mm., pubescent; stigmas 1–2 mm. long.
Seeds glabrous; testa covered with a very shallow reticulate pattern.
Perennial herb; stems stoloniferous, creeping and scrambling, longitudinally furrowed, pilose or hispid.
Diffuse perennial herb, stems stoloniferous, rooting at some of the nodes, thinly pilose with spreading eglandular hairs. Stipules ovate, acute to acuminate. Leaves with petioles ±10-150 mm long, pilose with spreading eglandular hairs, towards the tips underlain by shorter retrorse hairs; blade up to ±50 mm in diam., divided at least J of the way to the base into 5 lobes, lobes elliptic in outline, further lobed and toothed, thinly pilose on both surfaces. Peduncles in the axils of the leaves, ±30-70 mm long, usually 2-flowered, sometimes compounded, thinly pilose with long spreading eglandular hairs underlain by shorter retrorse ones. Pedicels ±10-30 mm long, pilose with retrorse hairs. Sepals ±6 x 2.5 mm, pilose with spreading hairs. Petals 5 x 2.5 mm in the local specimen, ±10 x 5-7 mm fide Laundon (op. cit.), obovate, entire or very shallowly notched, white or pink. Rostrum pubescent.
Geranium arabicum is widespread from Yemen to Eritrea, Sudan, Ethiopia, the mountains of tropical Africa, south to Zimbabwe, and west to West Africa; it is also in Madagascar. This solitary record from southern Africa, on the Transkeian coast at Port St Johns, is remarkable and needs confirmation.