Flora of Dominica, Part 2 - Smithsonian Institution Libraries

NUMBER 77 ASTERACEAE 33
43. Heads larger (to 1 cm long); achenes prismatic . . Pluchea
42. Heads homogamous (only 1 type of floret in each head).
44. Leaves 3-veined; plants dioecious . . . . , . . . Baccharis
44. Leaves pinnately veined, plants monoecious . . . Vernonia
Acanthospermum Schrank
Acanthospermum hispidum
Acanthospermwn hispidwn A.P. Candolle, 1836,5:522.-Blake, 1921:386.
Annual pubescent herbs; leaves to 3 cm long, opposite,
obscurely serrate, gradually tapered to base; heads axillary,
sessile; involucre double, outer 5 bracts herbaceous and inner
bracts becoming burr-like, each enclosing an achene; receptacle
with pales; ray-florets yellowish, few and inconspicuous;
disk-florets appearing bisexual but sterile; pappus 0; fruits
(achene enclosed in involucral bract) armed with 2 elongated
terminal spines and marginal hooks.
Widely spread neotropical weed from U.S.A. to Argentina,
now Africa and Hawaii; collected as “uncommon” in Dominica:
Roseau city limits (King 6290).
Acmella L. Richard
Acmella uliginosa
Acmella uliginosa (Swam) Cassini in Cuvier, 1822,24:331.-Jansen, 198555.
Spilanthes uliginosa Swartz, 1788:llO.-A. Moore. 1907:537.--DOmin,
1930d371.
Small annual herbs; leaves opposite, lanceolate to narrowly
ovate, sermlate; heads long-peduncled, terminal or in upper
mils; involucral bracts 5-6, 1-seriate; receptacle elongated,
pales stramineous, enclosing and longer than achenes but
finally deciduous; ray-florets female, yellow, f equaling
involucre; disk-florets yellow, 4-merous, bisexual; achenes
black, compressed, ciliate on both margins, pappus 2-awned.
Widespread in tropics; in disturbed areas of Dominica in wet
places: Goodwill (Eggers 74), Grand Fond (King 6375), Pont
Cass6 (Chambers2716), Portsmouth (Hodge 722), Rosalie Bay
(Wilbur 8331), Soufriere (Lloyd 473), Sylvania (Hodge 721).
Adjanohoun et al. (1985:91, pl. 57) reported medicinal usage
(as Spilanthes uliginosa).
Ageratum Linnaeus
Ageratum conyzoides
Ageratum conyzoides Linnaeus, 1753:839.--Domin, 1930d:63.-M.F. Johns
~ , 1971:26.
Bouton.
Herb; leaves opposite; florets mauve or white, all tubular
(disk); involucre multiseriate; receptacle naked, achenes 5-
ribbed, black with 5 (awned in ours) scales.
Pantropical weed; common in Dominica in low to middle
elevations: Bellevue (King 1603), Cabrit Swamp (Hodge 751),
Carib Reserve (Hodge 3394), Fond Baron Estate (King 6299),
Freshwater Lake road (Chambers 2674,2675), Laudat (Hodge
1805, 1806, King 6386), Lisdara (Hodge 755, 2337), Marigot
(Hodge 752), Mount Joy (Hodge 1270, 1274), Pointe Ronde
(Hodge 2681), Pont Casd (Erst 1236, Hodge 1200, King
6350), Portsmouth (Hodge 754, Ridgefield (Hodge 2185),
Roseau (Hodge 753, King 6289, Lloyd 556), South Chiltem
(Ernst 1321, Hodge 750, 1452), Springfield (King 6340),
Sylvania (Cooper 2, 77, Hodge 750), Syndicate (Chambers
2655, Whitefoord 3606), Tete Morne (King 6323).
Adjanohoun et al. (1985:67, pl. 33) reported medicinal use of
infusions and decoctions.
Several collectors comment that white- and blue-flowered
phases occur in the Same populations without intermediates.
The species is sometimes confused with Fleischmannia
microstemon but in that the achenes are toppi by a capillary
pappus, not scales.
Ambrosia Linnaeus
1. Plants creeping; lower leaves tripinnatifid . . . A. hispida
1. Plants erect; lower leaves bipinnatifid . . . A. peruviana
Ambrosia hispida
Ambrosia hispida Punh, 1814743.-Domin, 1930d59.
Hispid, monoecious herbs; leaves alternate, finely lobed;
pistillate heads clustered, 1-flowered, usually armed with 4-8
tubercles or spines, corolla 0, stamens 0, pappus 0; staminate
heads many-flowered, dense on undivided racemes, corolla
tubular; achenes black.
Weed of Caribbean strands, sometimes cultivated; on
Dominica: sine loc. (Nicholls I1 cited by Domin, l.c., not seen).
An infusion is used by Caribs as a vermifuge and febrifuge
(Hodge and Taylor, 1957:614). Adjanohoun et al. (1985:69, pl.
35) confirmed this.
Ambrosia peruviana
Ambrosia perwiana Willdenow, 1805,4:377.
Ambrosia paniculata sensu auctt.. non Michaux, nom. superfl. pro Iw
monophylla Walter [= A. artctnisiifdia Linnaeus].Stehle,1954b:77.
Ambrosia pniculata var. perrcviana (Willdenow) 0. Schulz in Urban, 19 11,
7:m.
Ambrosia cumanensis Kunth, 1820,4:216.-hin, 193W59.
Ambrosia pniculaia var. cmnensis (Kmth) 0. Schulz in Urban, 1911,7536.
Pubescent, erect plant; leaves less finely divided; male heads