How to determine if you have Bocking 4 or Bocking 14 Comfrey

For those who don't know, Bocking 4 and Bocking 14 comfrey varieties are Sterile Hybrids that can't reproduce by seed, but propagate SUPER easily by root/stem/etc cuttings.

Below are descriptions of these two varieties in question, taken from "COMFREY: Past, Present and Future" by Lawrence D. Hills (the person originally responsible for the Bocking varieties):

Bocking No. 14
This is the dominant in the Stephenson strain, 80 to 90 per cent. The flower stems are slender and frequent and are entirely
wingless. The flowers are Imperial Purple 33/3 fading to Lilac Purple 031/3. The leaves are pointed, slightly serrated at the
edges and vary in proportion from 5 to 12 and 3 to 6.
This is also the clone presented by Mr. W. Holmes of the Hannah Dairy Research Institute to the Holbrook Young
Farmers’ Club for their trial from his survivals. Its flower colour is not blue as stated by Mr. Holmes in Agriculture for
February 1946. Because his trials were undertaken in grass for an unmeasured proportion of the half acre devoted to the
crop, and he used close planting, his results cannot be compared with those of good farmers.
The balance of the Stephenson Strain is made up of variations found also in the Webster, the two stemmy and small
winged or wingless variations, Nos. 5 and 7, plus the thick stemmed winged varieties Nos. 4 and 6. There is, however, one
special variation.

Fig. 5 Bocking No. 14 takes after Symphytum asperrimum in flower stem habit. It is early , rust resistant, and high in potash and allantoin, the healing principle.



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Bocking No. 4
This is the dominant in the strain, about 50 to 60 per cent. The flower colour is Bishops Violet 34/3 when fully open. It has
strong stems and small wings. The leaves are broad and round tipped, their proportion is 5 to 10, but they have no incurling,
therefore they appear far wider than a No. 1 for example. The edges are unserrated, and the veins are prominent, with
bristles thickest on the underside so that they appear smooth. At leafy stage these leaves are very large, recovering rapidly
after cutting. The stems, as in all the variations under trial, are solid (see Fig. 7 overleaf).

Fig. 7 Bocking No. 4 has thick stems like Symphytum officinale, but without the distinctive ‘wings’. It is preferred by poultry and for human food, with more protein and less allantoin.

After reading the aforementioned book, I've decided that I have Bocking 14 for the following reasons:
1) my flowers start as Imperial Purple and fade to Lilac Purple 2) my flower stems are slender and frequent 3) The leaves are pointed and spikey at the edges.
Compared to Bocking 4, I think my variety is slightly taller probably puts up more stems.  The flowers aren't a "Bishops Violet" when fully open.  I think the "wings" are much larger than Bocking 4.  The leaves aren't broad or round tipped.


These are some pictures of my Bocking 14 Comfrey:










If you have some pictures of your own Bocking comfrey, please share.

>> If you have some pictures of your own Bocking comfrey, please share.


Sure!  Here's one of my patches of Bocking 14.  

The same patch, one month later: