Amentotaxus argotaenia Seeds | Catkin Yew
LATIN NAME: Amentotaxus argotaenia
COMMON NAME: Catkin Yew
Plant Profile
The name Amentotaxus is a description in two halves: amentum, a catkin, and taxus, the yew. It fits. This is a yew relative that hangs its male cones in long catkin-like spikes, a structure no true yew has. Amentotaxus argotaenia was the first of the group to be described, and it remains the type species of a genus with only a handful of survivors.
Henry Fletcher Hance first described the plant as a species of Cephalotaxus, and Ernst Georg Pilger later made it the type of a new genus. Modern treatments recognise a handful of species: the widespread argotaenia, yunnanensis in the southwest, a Taiwanese form, and two more in Vietnam and Laos. The genus is usually kept in Taxaceae and sometimes given its own family, which tells you how awkward its position remains.
The leaves are leathery and lance-shaped, set in two ranks along the shoot and drawn out to a soft point. Underneath, two broad glaucous-white bands of stomata run the length of the blade, divided by a narrow green midrib; the contrast is strong enough to identify a plant from below without touching it. Above, the leaf is a dull dark green with a raised central vein.
Male and female cones sit on different plants. Female ovules are borne in pairs on a short stalk, each wrapped in a fleshy aril that swells and colours as the seed ripens, and birds take the aril and scatter the hard seed. Male cones hang in the long spikes that give the genus its name, clustered along the underside of the shoot in spring.
Amentotaxus argotaenia grows in the shade of evergreen broad-leaved forest, mostly in ravines and on damp slopes below about 1,500 metres, on acid soils deep in leaf litter. Plants are usually scattered individuals rather than populations, and the species is treated as vulnerable. It survives well inside protected country parks in Hong Kong, one reason its situation there is better documented than on the mainland.
Science & Biotechnology
The genus gave its name to a molecule. Amentoflavone is a biflavone, two flavone units joined into one large flat structure, and it was first obtained from these plants, which is why it carries the genus name. It occurs widely elsewhere, in ginkgo and in clubmosses, and it is studied for anti-inflammatory and antiviral activity. Related biflavones, including hinokiflavone and sciadopitysin, also occur in the family.
Because the species are few and hard to tell apart, molecular work has done much of the sorting. Plastid genomes have been assembled for the genus and used to test whether the broadly drawn argotaenia is really one species; the answer so far is that it holds more variation than its morphology suggests, and that some populations long called argotaenia sit closer to other species. Field botanists now check locality as carefully as leaf shape.
Slow growth, scattered plants and a small seed crop make the genus a candidate for laboratory help. Tissue culture has been used to multiply rare Taxaceae from small pieces of shoot, and the same approach offers a way to build up planting stock without removing plants from the wild. Seed remains the simpler route for a garden, though it demands shade and patience.
Uses & Benefits
Grow it as a woodland curiosity. It wants acid, humus-rich soil in deep shade, shelter from wind, and moisture that never quite dries out. It will never be a crop, and it has no timber value worth the cutting; its role is in a conservation collection, a shaded ravine planting, or the sort of garden where rarity itself is the point.
Growing from Seed
Clean the seed as soon as the aril softens, rubbing it away in water until the hard coat is bare, because pulp left on the seed rots and takes the embryo with it. Sow into a mix of chopped moss, sieved leaf mould and perlite, pressing each seed on edge just under the surface, and keep the pan in a shaded frame where the air stays humid.
Water with rainwater and keep the medium damp rather than wet. Once the seedlings have made a firm tuft of leaves, move them into deep pots of the same mix and keep them under shade for another season. Plant out only when the plants are about a hand high, spacing them a metre apart, and mulch with leaf mould. Protect them from winter sun and from slugs, which graze young conifer foliage.
Our Take
If you grow one of the catkin yews, the rest of the genus becomes interesting rather than academic. Amentotaxus yunnanensis is the southwestern species, with broader leaves and a range that reaches into Yunnan and Vietnam. Cephalotaxus fortunei shares the same shaded ground and grows much faster, and Torreya grandis adds an edible nut to the family. Sow them in the same shaded bed and compare the undersides of the leaves.
Related Reading
Continue exploring with these related plants: