They range from small cushion plants to tall flower spikes surrounded by rosettes of stiff, pointed leaves, the latter probably adaptations to prevent browsing by moa.

Like other species in the family Apiaceae, speargrasses have taproots and small flowers, which are clustered into inflorescences called umbels.

[5] Many species of speargrass have tough, rigid leaves and flower bracts tipped with long sharp spikes, arranged in one or more rosettes which present spines in every direction.

[2] Long spines are known to deter ratite birds from browsing other plants,[7] and the two large-leaved species endemic to the Chatham Islands, which never had moa, have soft leaves without spikes.

[11] The smaller Aciphylla species were not used as fragrance, although their taproot, known as papaī, was eaten–the red roots of taramea were considered too bitter.

It was collected by cutting or burning plants in the evening, and gathering the exuded gum (called pia) in the morning.

[13] The collected oil hardened into a resin, ware-taramea, or could be mixed with animal fat (from kererū, tītī,[12] weka, tūī, or kiore) to preserve the fragrance.

[11] It could also be stored in a hollow bone or bunch of feathers, and when warmed by body heat gave off a pleasant fragrance.

The decline of A. squarrosa on the mainland and predation by rats and mice had reduced the North Island L. huttoni population by the 2000s to around 150 individuals, living on cliffs of Wellington's south coast.