Eryngium L.
Glabrous annual, biennial or perennial herbs. Lvs simple, entire, pinnate or palmately lobed, usually spinous. Fls sessile in capitula, these solitary or in cymes or racemes; bracts in one or more series subtending the head, usually spinous; bracteoles subtending fls usually spinous, entire or 3-fid. Petals white to purple or greenish, regular, variously lobed or fringed, inflexed; calyx teeth evident, usually acute, rarely spinescent, > petals. Fr. ovoid to subglobose, scarcely flattened laterally, variously covered with scales, spines or tubercles; commissure broad; ribs obscure; vittae usually solitary.
Key
c. 230 spp., temperate and tropical regions, excluding tropical and southern Africa. Native sp. 1, naturalised 3.
Many Eryngium spp. appear similar to thistles and early herbalists classified them as thistles. However, the resemblance is only superficial and eryngiums were moved to the company of carrots by Tournefort in 1694. Several spp. of this unusual genus are cultivated as garden ornamentals.
