Chenopodium ambrosioides, Shortly

Brenan, J. P. M, 1954, Chenopodiaceae (part: Chenopodium), Flora of Tropical East Africa 12, pp. 2-14 : 10-11

publication ID

https://doi.org/10.5281/zenodo.6286024

DOI

https://doi.org/10.5281/zenodo.6286024

persistent identifier

https://treatment.plazi.org/id/3FE33F46-2F86-5A90-EF84-16E87FC40CD4

treatment provided by

Donat

scientific name

Chenopodium ambrosioides
status

 

forma ambrosioides Shortly and inconspicuously pubescent or puberulous, sometimes with some longer hairs on stem. Leaves mostly lanceolate, lower with more or less coarse irregular ascending teeth, upper becoming entire. Flower-clusters all or mostly bracteate. Sepals not at all keeled. Seeds (Fig. 2/5, p. 3) deep red-brown, about 0.5-0.8 mm. in diameter, testa under microscope almost smooth and with faintly impressed sinuose lines.

Uganda. Masaka District : Koki, Buyamba, Aug. 1945, Purseglove, 1787 ! ; Mengo District : Kampala, 26 May 1933, A, S, Thomas 1219 !

Kenya. Nairobi, July 1943, Nattrass 254 in G.M. 15650 !

Tanganyika. Shinyanga, Koritschoner 2006 ! ; Tabora District : Nyembe, 6 June 1913, Braun 5417 !

Distb. U4 ; E4 ; Tl, 4, 6 ; throughout the tropical and subtropical regions of the world ; especially polymorphic in America Hâb. A weed near habitations, sometimes on permanent ways. Certainly not native ; altitude range incompletely known, but recorded at about 1220 m.

Our plants are all, according to the nomenclature of Aellen in F.R. 26 : 33-34 (1929) and of Aellen & Just in Amer. Midi. Nat. 30 : 51-52 (1943), C. ambrosioides subsp. eu-ambrosioides Aellen var. typicum (Speg.) Aellen f. genuinum (Willk.) Aellen .

Hauman in F.C.B. 2 : 3 (1951) reports the same for the Belgian Congo. The uniformity in Africa is in strong and suggestive contrast with the great variation in America. Since al the ranks of the hierarchy given by Aellen include the type of the species, for each and all the epithet must be ambrosioïdes unaltered.

The conception of C. ambrosioides adopted here follows the papers of Aellen and of Aellen & Just already mentioned, and is not that of Woroschilov*s revision of the species of Chenopodium sect. Ambrina (Spach) Hook, f. , in Joum. Bot. U.R.S.S. 27 : 33-47 (1942).

Besides in the points mentioned in the description above C. ambrosioides differs from all the other East African species in the ovary being glandular above not smooth, and in the stigmas being mostly 3-4, not constantly 2.