Introduction

The genus Striga Lour. belongs to the family Orobanchaceae (broomrape family), and consists of about 34 species worldwide POWO (2018) with its centre of diversity in tropical Africa. Previously, the genus was accommodated in the family Scrophulariaceae, but based on molecular and morphological data was transferred to Orobanchaceae (Olmstead et al. 2001). To date, seven species have been recorded for the Indian flora.

One of the species Striga asiatica (L.) Kuntze, based on Buchnera asiatica L., was typified by Hepper (1974). There is however no evidence that the specimen was seen by Linnaeus when describing the species. Linnaeus (1753) published two names in Buchnera [Buchnera americana L. (1753: 630) and B. asiatica L. (1753: 630)] in his Species Plantarum, of which B. asiatica is now referred to the genus Striga. Linnaeus’s protologue of B. asiatica (1753, Fig. 1) consisted of a short diagnosis “BUCHNERA foliis integerrimis alternis”, along with the provenance information “Habitat in Zeylona, China”, and a detailed description. There are five herbarium sheets conserved at the Linnaean Herbarium (LINN-HL790.10, LINN-HL790.11, LINN-HL790.13, LINN-HL790.14 and LINN-HL790.15) in the name B. asiatica, but these are post-1753 additions to the Herbarium and are not original material for the name B. asiatica, as has been indicated by Jarvis (2007). The three sheets LINN-HL790.11, LINN-HL790.14 and LINN-HL790.15 were collected by J. G. Koenig from India, LINN-HL790.13 by C. P. Thunberg from Sri Lanka, and LINN-HL790.10 by an anonymous collector from an unknown locality.

Fig. 1
figure 1

Protologue of Buchnera asiatica by Linnaeus (1753: 630).

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Hepper (1974) cited the type for the Linnaean name Buchnera asiatica as “Type. Comoro Islands, St. Joanna, Toreen LINN. (Savage Cat. No. 790/10 partly)”. The herbarium sheet LINN-HL790.10 consists of five specimens: the left hand side, bigger specimen is the type of B. asiatica as per Hepper. The upper two specimens on the right hand side are of B. asiatica and the lower two are of Striga densiflora (Benth.) Benth. (= Buchnera densiflora Benth.). This sheet lacks annotion of the number 2 (Species Plantarum number of this species) by Linnaeus and is also a mixed collection of two species Striga asiatica and S. densiflora. According to Jarvis (2007), Turland (2006), Turland & Jarvis (1997), Stearn (1957) and many others, Linnaean specimens which were in Linnaeus’s possession before the publication of Species Plantarum, were usually annotated by Linnaeus with the Species Plantarum number of that species. Furthermore, the herbarium sheet LINN-HL790.10 is annotated by Linnaeus as “Buchnera asiatica” and from this annotation it is clear that this specimen is a post-1753 addition because specimens in Linnaeus’s possession before the publication of Species Plantarum were usually not annotated by him with full binomial names. Moreover, Hepper (1974) mentioned the locality for the type specimen as “Comoro Islands, St. Joanna” and collector as Olaf Toren, but Linnaeus mentioned “Zeylona, China” in the protologue of B. Asiatica; Olaf Toren (1718 – 1753) collected plant specimens from China and India (Surat and Malabar), not from the Comoro Islands (Bretschneider 1898; Stafleu & Cowan 1986).

This is the reason why earlier Saldanha (1963) and Cramer (1981) treated the name Buchnera asiatica as ambiguous, and Saldanha (1963) proposed to reject the name B. asiatica. Therefore, the earlier type designated by Hepper (1974) should be rejected because it is now clear that this sheet/specimen was not in the hand of Linnaeus at the time of describing the name B. asiatica. Only one herbarium sheet relevant to the Linnaean name Buchnera asiatica can be traced at S (S-LINN-09-25827) which is annotated by Linnaeus as “2 Buch. asiatica” — the number 2 corresponds with the Species Plantarum number of this species. Thus, it is designated here as lectotype for the name Buchnera asiatica as it agrees well with the diagnosis and description given in the protologue by Linnaeus, and also depicts the taxon as recognised today.

Lectotypification

Striga asiatica (L.) Kuntze (1891: 466). Buchnera asiatica L. (Linnaeus 1753: 630). Lectotype (designated here): S-LINN-09-25827 [digital image!], Fig. 2.

Fig. 2
figure 2

Lectotype of Buchnera asiatica L. (S-LINN-09-25827, © Swedish Museum of Natural History, Stockholm).

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