Plant profiles > Anisotome

Family : Apiaceae

One doesn't need to be the most perceptive soul to ascertain that this genus belongs to the carrot family, as many of its members are similar in appearance to celery, fennel and carrot (albeit usually in a more elegant package). Such a comparison may not instil a burning desire amongst many gardeners to plant an Anisotome in their garden - as we can easily ignore the aesthetic value of vegetables (due to the fact that they are primarily cultivated for prosaic reasons).

However, when one considers foliage in terms of texture, the appeal of umbellifers (as members of the carrot family are commonly known) becomes much more apparent. The feathery, fern-like leaves that many species bear can act as a lightweight foil to bolder plants, as well as playing a connective role within plantings (their filigreed leaf structure acts as 'aesthetic glue').

There are c. 16 species of Anisotome, all of them confined to the New Zealand botanical province (including three impressive species that are only found in the Subantarctic Islands).

Anisotome patula

Searching for this little blue-leaved herb in the wild turned out to be a good example of the value of persistence. Just at the point in time that I thought I had little chance of finding it (without venturing up to some life-threatening cliffs much further up in the reserve), I decided that I'd have a final look in what seemed an unpromising grassy section of slope that stood above a section of cliff.

According to material that I had read1, this is a species of very open ground (such as the steep rock face in the photo below, left); and for that reason, I did not expect to see it emerging from the grassy sward in which several specimens of A. patula were growing. Further investigation showed a fairly extensive population was growing in a range of positions along the upper part of the cliffs, including sheer rockfaces, on top of rocks, and in grassland.

It is worth noting that the grassed areas in which A. patula grows are covered in much finer-leaved grasses than the coarse pasture of adjoining farmland - and there is a distinct change in the makeup of grass species within 5 to 10m of the top of cliffs (where conditions no doubt become seasonally drier, as the drought-prone 'calcareous'2 soils become shallower).

Anisotome patula is special to limestone habitats of the South Canterbury area3 (including Pareora, where these photographs were taken), with a historical record from Burkes Pass in inland Canterbury (at the fringe of the Mackenzie Basin). It was this record from Burkes Pass that stimulated my interest in planting this species (at the garden that we planted at Tekapo), from material that Oratia Native Plant Nursery had introduced to cultivation.

Considering the climatic differences between the extremely dry Mackenzie Basin and the South Canterbury foothills (where this rare species endures), A. patula has performed surprisingly well in the open, dry position in the Tekapo garden in which it has been planted. Its main claim for inclusion in gardens is the delicate, bluish-grey foliage, that can form an attractive detail on the ground plane of plantings.

The status of this species has not always been clearcut, and is an example of how boundaries between species (and even genera) are not necessarily as convenient as we might assume. Whilst some botanists have included it as a distinct species within Anisotome (where it currently resides), others (including John Dawson, who has done much of the work on New Zealand umbellifers) have considered it to lie within a different, but closely related, genus (Gingidia).

 


Footnotes

  1. The most authoritative of which is the NZ Plant Conservation Network's excellent website, www. nzpcn.org.nz.
  2. The term 'calcareous' refers to soils that are derived from, and associated with, limestone. Although typically fertile in dry regions, they do not hold water readily.
  3. This was the status of its distribution at the time of writing; although information on this may change in the future, according to the NZPCN website.