Plants monocarpic, annual, height in flower (6–)10–20(–25) mm. Caudex unbranched. Taproot slender. Flowering stems terminal only or terminal and lateral, 1–4 per plant, stem colour yellow, lateral flowering stems erect or decumbent, c. 0.6 mm diam. when dry; flowering stem leaves 1–2 pairs per stem, lowest pedicels from near apex of flowering stem. Rosette of leaves absent from flowering plants, leaves linear or narrowly elliptic, (1.5–)3.5–8.0(–13) mm long, (0.5–)1.0–2.0 mm wide, flat, not recurved, petiole indistinct, 2–7 mm long, 0.4–0.6 mm wide at leaf base. Flowering stem leaves narrower than leaves. Pedicels 0.7–1.7 mm long, c. 0.5 mm diam., c. 0.45 mm diam. when dry. Flowers 1(–4) per plant, 3.7–5.0 mm long. Calyx 4–5-lobed, 2.4–6.2 mm long, green tinted purpleblack, hairs at calyx–corolla fusion line absent; lobes 1.0–3.3 mm long, 0.95–2.1 mm wide at base, plane, apices acute, margins smooth, sinus hairs absent. Corolla 3.4–4.3 mm long, white, veins uncoloured; tube 1.4–3.2 mm long; 4–5-lobed, lobes 2.0–3.6 mm long, 1.3–2.3 mm wide, hairs below sinus absent; nectary 0.6–1.0 mm from corolla base. Filaments 1.9–4.1 mm long from corolla base, 0.2–0.3 mm wide. Anthers 0.4–0.7 mm long, introrse at anthesis. Ovules 2–4(–13) per ovary. Stigma colour unknown. Capsule 4.0–6.0 mm long. FL Jan–Feb.

Erect, slender, glabrous, annual herb (6)-10-20- (25) mm tall, usually with a simple stem and a solitary terminal flower, very rarely branched and with 2-5 flowers. Leaves usually all cauline, sometimes congested at base, in 3-6-(9) opposite pairs, apetiolate, (1.5)-3.5-8-(13) × (0.5)-1-2 mm, spathulate, obtuse, slightly narrowed to base, green or tinged purplish, fleshy, dull, with distinct mid-vein. Uppermost leaves sometimes reduced to bracts. Pedicel (1)—3—8 mm long. Flowers 4-(5)-merous. Calyx (1.5)—3- 5-(6) mm long, cut to 2/5-½ way; lobes triangular to ovate-triangular, acute, erect at fruiting; sinuses acute. Petals (2.5)-4-6-(7) mm long, exceeding calyx by 1-1.5 mm, white, cut to c. ½ way; lobes ovatetriangular. Capsule ovate-elliptic, brown, dehiscent from apex. Seeds 0.5-1 mm diameter, globular to ovoid, slightly rough.

Herba minuta annua, plerumque caule simplici floreque solitario terminali rarissime 2-5 floribus induta. Folia plerumque omnia caulina, in 3-6-(9) paribis oppositis disposita, spathulata. Flores4-(5)-meii. Calyx per 2/5- ½ longitudinis sui dissec tus. Petala alba, ad c. ½ dissecta. A G.filipede differt statura plerumque breviore, floribus paucioribus plerumque 4-meris, calyce corollaque minus dissecta.