Chenopodium vulvaria var. incisum Maire

Chatelain, Cyrille, Uotila, Pertti, Benhouhou, Salima, Mombrial, Florian, Mesbah, Melilia, Baa, Soumaya & Benghanem, Abdelkader Nabil, 2022, Chenopodium hoggarense (Amaranthaceae), a new species from Algeria and Chad, Willdenowia 52 (1), pp. 75-81 : 79-81

Chenopodium vulvaria var. incisum Maire in Bull. Soc. Hist. Nat. Afrique N. 34: 184. 1943. – Lectotype (designated here): Algeria, in montibus Ahaggar Tazerouk, in alveo arenoso aminis , 1900–1950 m, 20 Mar 1928, Maire 1067 ( P [ P04940937 ]!, isolectotype: MPU [ MPU005496 ]! ).

Remarks — Maire (1943) described Chenopodium vulvaria var. incisum from Hoggar and Tefedest with the description given in Maire (1933), but without the reference to C. opulifolium . Further, he did not mention anything of the smell, but the placement of the variety under C. vulvaria might at least suggest the presence of a similar smell. He also noted that this plant was mentioned unnamed in his study from the central Sahara in 1933 and that it grows also in Tibesti. He reproduced the same description and geographical information in his Flore de l’Afrique du Nord ( Maire 1962), in which he accepted var. incisum as the only lower taxon of C. vulvaria from the central Sahara. However, neither the type material of var. incisum nor the specimens determined by Maire as var. incisum belong to C. vulvaria s.lat.

The specimens collected or determined by Maire seem to represent two kinds of plants, one with almost entire leaves (typical Chenopodium hoggarense) and another with three-lobed leaves (typical var. incisum). In growth habit and type of inflorescence, var. incisum resembles C. hoggarense, which is also the case if they both have a similar smell. But the distinctly three-lobed leaves of var. incisum do not match the plants of C. hoggarense seen in 2019 or many other specimens, all with fully or almost entire leaves. However, such leaf dimorphism is not completely unknown in Chenopodium, e.g. seen at least in Asiatic C. novopokrovskyanum (Aellen) Uotila and North American C. pratericola Rydb.

Chenopodium opulifolium and C. vulvaria var. incisum resemble each other because they can both be strongly farinose and may have three-lobed leaves with acute or even mucronate apices. But the leaves of C. opulifolium are as broad as long, sometimes even broader, and the margins are more distinctly dentate, whereas leaves of var. incisum are only narrowly three-lobed, otherwise weakly dentate if at all. Furthermore, the growth habit of C. opulifolium is usually strongly branched, the branches long and fairly spreading, also in the inflorescence, whereas var. incisum has only short branches from basal parts of the stem and the branches of the inflorescence are short and erectopatent. Maire (1962) reported C. opulifolium only from the N part of North Africa. However, the variation in characters of C. opulifolium in North Africa seems to be different and wider than is typically reported from Europe. Even C. album occurs in North Africa. It is variable and the growth habit may resemble that of var. incisum. But its leaves are larger, with variable shape and dentation, but never in the combination seen in var. incisum.

Because there are some doubts about the identity of Chenopodium vulvaria var. incisum, its position is left open here.

Uses — Gast & al. (1972) and Gast (2000) reported that Chenopodium vulvaria (under the name of Taouit, in Tamasheq), which grew on the slopes of the Atakor and of the Adrar des Ifoghas between 1000 and 2700 m, could be very abundant there in rainy years. Then seeds were collected in quantities by the Tuaregs of the Ahaggar and they ground flour from them to be used in pancakes or porridge-like cereal or to “bulk out” cereal dishes, e.g. mixed with wheat or millet. Gast (2000) also noted that flour/seeds lacked the smell, so unmistakably present in the leaves. Spare seeds were even sown deliberately for future crops. Seeds were also considered good against tropical fever, which is why people travelling by caravans to Sudan carried them as a medicinal plant. Obviously this plant is C. hoggarense, no other Chenopodium has been observed at this altitude in such quantities. The use and even sowing by Tuaregs may explain the occurrence of C. hoggarense in cultivated places, as reported by Maire (1933, as C. vulvaria ), and intentional carrying by caravans might have caused spreading along their routes.

Additional specimens examined — Algeria, Wilaya de Tamanrasset, Hoggar (without precise locality), Laperrine s.n. ( MPU [ MPU276164 ]); Montis Tefedest amnem Agelil in humidis, 1200 m, 11 Apr 1928, Maire 1063 ( MPU [ MPU276166 ] mixed with Chenopodiastrum murale ( L.) S. Fuentes & al.).