Flora of Dominica, Part 2 - Smithsonian Institution Libraries

NumER 77 ASTERACEAE 43
The combination is usually attributed to R. Brown but he did
not actually make it, as required by Art. 33.1 (XBN, cf. Ex. 2).
Parthenium Linnaeus
Parthenium hysterophorus
Partheniwn hysterophorw beus, 1753:988.4risebach, 1861 :369.-
Do&, 193od:72.--Rollins, 195052
Erect annual herbs; leaves alternate, 1-2-pinnately parted (to
simple above); heads many, small (to 0.5 cm across); involucral
bracts in 2 series, k equal; receptacle small, convex, with pales;
marginal florets white, female, ligules short, 2-toothed; central
florets functionally male; achenes black, obovoid, keeled on
inner face, with 2 scales.
Apparently originally native to Caribbean area but an
aggressive weed; common in disturbed, lowland areas of
Dominica: Bataka (Hodge 3189), Canefield (Hodge 730),
Goodwill (Erst 1277, King 6288), Grand Bay, Berekua (King
6318), Marigot (Hodge 729), Pringles Bay (Whitefoord 3739),
Scotts Head village (Hodge 1610, Soufrih (Lloyd 415).
Adjanohoun et al. (198587, pl. 53) reported medicinal
usages. Howard (1989, 6583) noted that the plant is often a
contact poison, causing itching and swelling.
Pectis Linnaeus
Pectis lingolia Linnaeus was reported for Dominica by
Urban (1907, 5286) as “Dominica et St. Lucia in litoralibus:
Duss n. 201, 932.” These are the basis for Stehl6 (1963:182)
citation. With Duss collections one can suspect a label error.
The species was again attributed to Dominica by Vdez
(1957:82), based on a statement by Britton and Wilson (1925,
6319), “West Indies south to Grenada.” No Dominican
specimens of this long-peduncled species have been seen.
1. Plants erect; leaves linear, >1.5 cm long . . . P. elongata
1. Plant prostrate; leaves oblanceolate,