Blackberries are notoriously difficult to identify, so this page is dedicated to describing the differences between two species that are found together on Keats Island: The European/Vested Blackkberry (Rubus vestitus) and the Himalayan Blackberry (tentatively Rubus bifrons). I made this guide to organize my own learning, so I hope it might be helpful to others as well.

Note on names:
The taxonomy of blackberries is very messy and complicated, because blackberries are able to reproduce asexually. This means that there are many different lineages of clones, and it is difficult to decide what counts as a species and where the limits are between different species. They can also hybridize and produce new hybrid lineages. The abundant introduced blackberries here in the Pacific Northwest are usually called "Himalayan Blackberry", but it is not clear exactly what species they are, or how many species/lineages have actually been introduced. They are often referred to as Rubus bifrons or Rubus armeniacus. I have no opinion on this as I am not a blackberry specialist, so I will refer to them as Rubus bifrons for simplicity, with the caveat that this name may prove incorrect once genetic studies have clarified which lineages are in our region and the taxonomy becomes settled... if it ever does! At any rate, these "Himalayan Blackberries" can be recognized and distinguished from Rubus vestitus which is also introduced here in Southwestern BC, and probably many other areas in the Pacific Northwest and elsewhere.

Primocanes vs Floricanes:
Before identifying a blackberry, it is necessary to know the difference between two types of branches: primocanes and floricanes. These branches have different ID features, so looking at the wrong one can given you an incorrect ID. While blackberry bushes can live for many years, their individual branches live for only two years. In the first year, a shoot sprouts out from the ground and begins to grow as a long sprawling vine. This is the primocane, and it will not produce flowers. In its second year, that branch will switch to producing side branches that are tipped with flowers. Those are floricanes. At the end of the season, the entire branch will die, ready to be replaced by the next one. As a result, the bottom of a blackberry thicket becomes full of dead branches. In summary, if you see flowers/fruits/buds on a branch, that is a floricane. The thick branches that are attached to the ground (i.e. they are not side branches) are primocanes.

Caveat:
All of these photos are taken on Keats Island in British Columbia, Canada. They represent the range of variation that we see here, but may not reflect the range of variation across other parts of the species range.

First, here is a quick summary of two key ID features:

Key feature #1: Hairs on primocanes

The easiest feature to check is the presence or absence of dense hairs on the primocanes. Rubus vestitus is covered in a vest of hairs that give it a fuzzy look. These catch the light and can be noticed even at a moderate distance. Himalayan Blackberry have hairless primocanes, giving them a sharper look. Beware that both species including Himalayan Blackberry do have hair on the floricanes, so make sure that you are looking at the primocanes - the branches that are very thick and do not have berries/flowers/buds. Himalayan Blackberry can have some scattered hairs on the primocanes, but is not densely hairy.

This photo shows the hairy primocanes on Rubus vestitus

This photo shows the lack of hairiness on Himalayan Blackberry.

Key feature #2: Stipitate glands in inflorescence

This ID mark is harder to see, but still very useful. If you look very very closely at the inflorescence of Rubus vestitus, you will see numerous stipitate glands amongst the hairs. These are tiny sticky globs suspended upon long stalks. Himalayan Blackberry lack these stipitate glands. Both species have hairs in the inflorescence, so it is necessary to look very closely to differentiate them from stipitate glands: Hairs end in a fine point without a sticky blob at the top, and the stalks of the stipitate glands are thicker and shorter than the hairs. You might be able to make them out with an extremely keen look with bare eyes, but it is much easier to zoom in with a magnifying glass or macro lens. I turn my binoculars backwards to use it like a microscope - it may look silly but works very well: put what you want to look at right up against the eyepiece and look through the wrong end of the binoculars. You can find the stipitate glands (or lack thereof) on the pedicels or the branch within the inflorescence of Rubus vestitus.

Here is what the stipitate glands look like on Rubus vestitus:

Compare to the lack of stipitate glands on this Himalayan Blackberry:

Detailed photo accounts

These species accounts contain my observations of the species on Keats Island. I included a lot of extra detail that is not necessary for a quick ID, but might be helpful for tricky cases.

Rubus vestitus

This species has the common name "European Blackberry", which is a bit nonsensical given how many hundreds of species live in Europe. An alternative named is "Vested Blackberry", coined by Stewart Wechsler, alluding to the vest of hairs around the stems that is key to their identification.

Floricane

The floricane is the stem that produces flowers/fruit. They are usually shorter than primocanes, and end in a single inflorescence. There are often many floricanes coming from the same primocane. They have several evenly spaced leaves arranged in an alternate pattern. In the axil of each leaf is a bud, and these buds grow into the pedicels of a single flower, or a short branch with 3 flowers.

Floricane: Flowers

The flowers of Rubus vestitus are pink, and can vary from deep magenta to nearly-white with only the faintest blush of pink. On plants with nearly-white flowers, the newly opening buds may be pinker than the fully expanded petals of older flowers. The flowers generally have dark pink stamens, but paler flowers can have white stamens.

While they normally have 5 petals, flowers with extra petals are common.

The sepals end in a point, giving the buds a beaked appearance. I've noticed that the pointed tip of the sepals is longer on the Keats Island Rubus vestitus than it is on the Himalayan Blackberries, and also that the sepals have prickles that the Himalayan Blackberries lack, but I don't know how consistent these differences are in other populations.

The inflorescence is at the tips of the floricane branches (terminal) and can have 7-35 flowers/fruits. The flowers are clustered (technically, cymiform or thyrsiform).

Floricane: Stipitate glands

The presence of stipitate glands in the inflorescence is an excellent field mark, but hard to see without a magnifier. These photos are at the limit of my camera's ability. I can sometimes just barely make them out with my bare eyes, but only after seeing what to look for under the magnifier. Since the stipitate glands are shorter than the hairs, it is also very difficult to feel the glands.

Stipitate glands can be found in the pedicels or branches within the inflorescence. They can also be found on the stem below the inflorescence, but become more sparse as you go down the stem away from the inflorescence, so require a closer search.

These photos are of the branch within the inflorescence (the branch in between individual flowers).

Floricane: floricane leaves

The floricane leaves usually consist of three leaflets. Less commonly, some leaves may be divided into five leaflets. The leaflets are variable in shape, but are generally more rounded than Himalayan Blackberry, particularly the terminal leaflet. The rounded leaves end with a short triangle at the apex.

The uppermost leaf sometimes is only a single leaflet (i.e., a simple leaf).

Like Himalayan Blackberry, they are hairy above and below, giving them a soft fuzzy feel on the top (adaxial) surface. The top seems fuzzier than Himalayan Blackberry leaves, at least on Keats Island.

The leaves farther down the branch (away from the growing tip) often have the lower leaflets more deeply lobed, almost dividing the leaf into 5 leaflets. Floricane leaves that are fully divided into five leaflets seem to be much more uncommon than on Himalayan, but they do occur.

The underside of the leaves (abaxial surface) are tomentose, giving them a gleaming silvery appearance. They are hairy, especially along the veins, and the midvein is armed with strong prickles.

At the base of each leaf is a pair of small stipules.

Floricane: floricanes branches

Like the primocanes, floricanes are hairy, prickly, and often maroon. Their dense layer of hair is denser than the branches of Himalayan Blackberry. While Himalayan blackberry also can have hairy floricane branches, the hair seems to be more scraggly and sparse, laying haphazardly along the stem, while the hair of Rubus vestitus is dense and erect in a smooth layer.

Primocane

Primocane: primocane leaves

The primocane leaves usually have five leaflets. The terminal leaflet is generally more rounded than it is in Himalayan Blackberry.

Prickly undersides:

When the leaves are growing, the terminal leaflet has a long point, but as the leaflet expands, it broadens into a broad oval that is less pointy than Himalayan Blackberry. Be sure to look at the shape of the older, fully expanded leaves lower or the stem, and ignore the shape of the immature leaves near the growing tips.

Primocane: primocane branches

Primocanes are strongly armed by prickes. The size of the prickle correlates with the size of the branch, with thinner, weaker prickles on the thin branches and strong, robust prickles that can tear clothing on the thicker branches. All branches have a dusting of fine hairs, even the thickest primocanes.

The colour of the branches can be deep maroon purple, especially in the sunlight. The shaded undersides of the branches can remain green, giving the branches a bicoloured pattern. Deeper branches in the shade can remain entirely green, especially those that creep along the ground. Branches can have any intermediate amount of red, and apparently some in Europe can be all green, but every bush I have seen on Keats Island have at least some maroon branches.

Closeup of prickles:

The growing tips of the primocanes are soft, flexible, and weak, with bendy prickles that cannot yet scratch. These growing tips are usually green, not maroon.

The dense covering of hairs gives the plant a frost-dusted appearance at a distance. The hairs catch the light, and make the plant sparkle with a camera flash.

Thickets

Like Himalayan Blackberry, Rubus vestitus can form impenetrable thickets.

Smaller sprawling canes can be found in the shaded understory

Himalayan Blackberry, Rubus bifrons

Note: it is not clear exactly which species our introduced "Himalayan Blackberry" correspond to, and there is a need for genetic studies to clarify this. I refer to them as Rubus bifrons for simplicity, but this could be proven wrong. They are sometimes referred to as Rubus armeniacus. They might even be neither species, or there could be more than one species!

Inflorescence

The pedicels and the branches within the inflorescence are densely covered by white hairs, similar to Rubus vestitus, but they lack stipitate glands.

The sepals are densely hairy, and end in a short point that makes the buds look beaked. On Keats Island, the Himalayan Blackberry tend to have shorter beaks than Rubus vestitus, but I do not know whether this is true of all populations.

The flowers have pale pink to white petals and white stamens. They do not seem to get as dark pink as Rubus vestitus can be.

The petals fall soon after flowering, leaving behind the tangle of stamens.

Floricane: floricane branches

The floricanes are hairy, like Rubus vestitus. This makes it important to determine whether you are looking at a primocane or a floricane before using the hairiness as an ID feature. The hair does seem to be messier and less dense than Rubus vestitus. The colour is variable, from bright green to red.

Floricane: Floricane leaves

Leaves of Himalayan Blackberry are pointier than mature Rubus vestitus leaves, particularly in the terminal leaflet. They may have 1, 3, or 5 leaflets, and vary along the stem. I often see simple leaves (1 leaflet) near the inflorescence, transitioning to 3 and then 5 leaflets farther down the stem, switching back to 3 leaflets near the base of the branch. Leaflet shape is variable, and beware that the leaves at the very base of the stem can be more rounded, similar to Rubus vestitus.

The top of the leaves can be covered in fine hairs. These hairs seem to be much less dense than Rubus vestitus, making them feel less fuzzy. At a distance, the leaves stand out when growing with Rubus vestitus, looking shinier or brighter green, and the veins stand out somewhat less.

The underside (abaxial surface) also has hairs, and prickles along the midvein.

At the base of each leaf is a pair of thin stipules.

Primocanes

The primocanes are much less hairy than Rubus vestitus, making them appear shinier at a distance. If you look very closely, you can still find a few hairs, but they are not as dense as Rubus vestitus.
The primocanes are often green, making them stand out when growing with maroon Rubus vestitus. The colour is variable, however, and the canes can be entirely red, especially when in the full sun. (Rubus vestitus can also be green.)

Primocane Leaves

Primocane leaves are generally divided into five leaflets. The terminal leaflet is pointed, giving it a different shape than the more rounded terminal leaflets of Rubus vestitus.

Thickets

Himalayan Blackberries can also form dense thickets.

On Keats Island, I often find them as just straggling plants among Salal and Rubus vestitus, and they have not started growing within the forest like Rubus vestitus has. There are a few dense thickets in sunny cleared areas.

References

Identifications are based on information in the Flora of North America:
(1) http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250100449

All photos are by Else Mikkelsen