Codonopsis available commercially in the UK are notoriously misnamed, a quick calculation on the plants and seed I have grown indicates that approximately 80% were not correctly named. However, one of the most misrepresented species is Codonopsis tangshen and this article is intended to throw some light on the situation and hopefully to locate the correct species.

C. tangshen is a species commonly listed in catalogues and seed lists and indeed I have grown many of them as my "live collection" list shows. It does not take too much study to realise that these plants tend to fall into one of two particular types, both of which do not match the botanical description of the correct species. Before I say more about this I will first talk about the actual species.

C. tangshen (Oliver) in Hook f. Icon. Pl. XX (1891) tab 1966 China Hupeh

It comes from central China and its roots are used by the Chinese for medicinal purposes. It is a vigorous climber to about 3m. and was described by T.F. Chipp in his 1908 "A Revision of the Genus Codonopsis" as follows:=

STEMS twinning, glabrous

LEAVES alternate or opposite, lanceolate with the base truncated, obtuse, obtusely serrate, pubescent or glabrous, ciliated, 5 to 8 cm. long, 2 to 3 cm. wide, petioles glabrous, 1-3 cm. long.

FLOWERS solitary, axillary, extra-axillary or opposite to the leaves, peduncles glabrous 3 to 4 cm. long.

CALYX inferior, almost divided to the base, lobes acute, glabrous 18-24 mm. long, 5-7 mm. wide.

COROLLA superior, bell shaped, green with purple spots, tube glabrous 1.5-2 cm. long in dried specimens, at the apex 2.5-3 cm. diameter, lobes triangular, acute 6-10 mm. long, 6-10 mm. wide.

FILAMENTS glabrous, 7-8 mm. long

ANTHERS glabrous 4-5 mm. long

STYLUS glabrous, purple

STIGMA 3-5 lobed

OVARY inferior, in the dried state 5-14mm. diam.

CAPSULE cone shaped, green or purple, 0.5-1.0 mm. wide in dried specimens

SEEDS elliptical, smooth, dark brown, 1-1.5 mm long, 0.5-1.0 mm. wide

The important thing to note here is the inferior calyx, almost divided to the base. This is an unusual feature for the genus and is the most obvious reason for discounting those species generally available in the UK. One of the herbarium specimens used by Chipp in his analysis is the E.H.Wilson collection no.1623 which I have seen and photographed along with another specimen collected by the Sino-American Botanical Expedition to Western Hupeh, China in 1980 (collection no. 186). These herbarium specimens are kept at the Royal Botanic Gardens at Edinburgh and the slides are shown below. Note that these are not type specimens.

• Notes on the slides on this webpage

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E.H.Wilson 1623                             SABE 186

These clearly show the calyx lobes (sepals) divided to the base of the stem just below the ovary and in the second picture the capsule can be seen swollen with the sepals hardly attached to it at all. The line drawing in Christopher Grey-Wilsons "A Survey of Codonopsis in Cultivation" also indicates this point.

By contrast plants going by the name C.tangshen have the sepals attached around the circumference of the capsule with a significant part of the ovary inferior to the calyx. It is my belief that that the imposters are sometimes C.pilosula (which is similar to tangshen in several ways) or more usually C.rotundifolia v. angustifolia, the latter also sometimes being labelled as C.meleagris hybrid, C. pilosula and even C. lanceolata but it appears to have become a "de facto" C. tangshen in the UK. I am still trying to locate a type specimen of C. rotundifolia v.angustifolia but the none types that I have seen match the misnamed plants generally attributed to C.tangshen quite closely.

A slide of the most common imposter is shown below. And next to it my drawing of how C.tangshen should look.

The left hand picture clearly shows the calyx lobes (sepals) not divided to the base of the stem, indeed there is a prominent hump between the sepals and the stem which forms part of the ovary. This definitely does not have an inferior calyx.

I would be very interested to hear comments on this subject and I am very keen to locate a plant or seed of the correct C. tangshen. If anyone can help I would be most pleased to receive an Email. (paul@kneebone.freeserve.co.uk)