Sylva Tellur., 111. 1838.

Common names: Spiderflower
Etymology: Greek, hemi- , half, and skolios, curved, alluding to seed shape
Treatment appears in FNA Volume 7. Treatment on page 220. Mentioned on page 195, 199, 200, 215.

Herbs, annual [perennial]. Stems (sometimes ± procumbent, weak), sparsely to moderately (or delicately) branched; glabrous or glandular-pubescent. Leaves: stipular spines present (recurved); petiole with pulvinus basally or distally; leaflets (1 or)3. Inflorescences terminal or axillary (from distal leaves), racemes (flat-topped or elongated); bracts present. Flowers (often appearing unisexual due to incomplete development), zygomorphic; sepals persistent or deciduous, distinct, equal (each often subtending a nectary); petals oblong to ovate, equal; stamens 6; filaments inserted on a discoid or conical gynophore, glabrous; anthers (ellipsoid to linear), coiling as pollen is released; gynophore reflexed in fruit. Fruits capsules, dehiscent, fusiform to linear-cylindric. Seeds 10–20, oblong or obovoid, prominently arillate, (cleft fused between ends). x = 10.


Introduced; Mexico, Central America, South America (south to Argentina).


species 6 (2 in the flora)

Selected References



1 Leaflet blade lanceolate-elliptic to ovate or rhombic; sepals lanceolate; anthers 2.5-4 mm; capsules (15-)25-40(-65) mm. Hemiscola aculeata
1 Leaflet blade obovate; sepals ovate; anthers 0.3-0.5 mm; capsules 15-20 mm. Hemiscola diffusa