Dicoma. | COMPOSIT# (Harv.) 515 
CXLIII. DICOMA, Less. 
Heads many-fl., homo- or hetero-gamous ; ray-fl., when present, neu- 
ter, ligulate, bilabiate or terete-tubular ; disc-/l. regular, 5-parted, the 
lobes longer than the tube: corollas very generally pubescent exter- 
nally. Znv, campanulate, equalling the dise ; the scales in many rows, 
coriaceous, obsoletely many-nerved, entire, acuminate, sometimes pun- 
gent, broad or narrow. ecept. honey-combed. Anthers long-tailed, the 
tails barbed; fil. glabrous. Style-branches short, erect, obtuse, exter- 
nally hispid ‘at the apex. <Achene turbinate, villous, beakless, often 1o- 
ridged. Pappus in 2 or many rows, of equal or unequal, shortly plu- 
mose bristles. DC. Prodr.7, p. 36. 
Small suffrutices or half-herbs. Leaves alternate, entire or toothed. Heads 
solitary. Name from 8s, twice, and kouy, hair; the double pappus of the first 
described species. 
Sect. 1. Sretrocoma. Heads discoid, ess marg. fl. wniseriate, sterile, 
very short, tubular or bilabiate. Pappus of the marg. fl. of scabrous bristles ; of 
the disc. fl. biseriate, the outer bristle-shaped, inner broad-based, more or less plin- 
mose. Procumbent, tomentose herbs. (Sp. 1-2.) 
Lys. on both sides woolly ; inner inv. sc. acute ; disc-papp. plu- 
mose beyond the middle oe ... (1) Capensis. 
Lys. becoming glabrous above ; inner iny. se. ‘taper-pointed ; 
disc-papp. ciliato-barbellate from base to apex ... «. .... (2) macrocephala. 
Sect. 2. RutciotHamnus. Heads radiate; rays neuter. Disc-pappus multiseriate, 
bristle-shaped, serrated. A much branched, erect, rigid half-shrub. (Sp. 3.) 
Lys. obovate or spathulate, thinly canous ; branches rib-striate (3) radiata. 
Sect. 3. Mactepium. Heads discoid, homogamous, Pappus of broadish, flat, 
subulate, acuminate, serrulate scales. Small, much-branched shrubs. (Sp. 4-6.) 
Leaves nerveless, broad-based, sessile, lanceolate, sabia 
concave ... ‘5 ..- (4) relhanioides. 
Leaves t-nerved, tapering at base, subpetiolate : 
Lys. obovate, woolly beneath ; no subulate bracts on the 
tee ee ... (5) diacanthoides. 
Lys. narrow, with revolute ‘margins, glabr. or tomentose : 
beneath ; many subulate bracts on the pedicels ... ... (6) Burmanni, 
Sect. 4. Psmnocoma. Heads discoid, homogamous. Pappus multiseriate, of very 
slender, “lliato-barbellate bristles. Jnv. sc. multiseriate, linear-subulate, midribbed, 
erect or squarrose. A diffuse half-shrub, 
Leaves linear or — tomentose ek serrulate, one- 
Reeve oe ee a tae .. «- (7) anomala, 
Sect. 5. Prerocoma. Heads discoid, homogamous. Pappus bristles conspicu- 
ously plumose. Erect herbs; stem simple or corymbose, one or several-headed. 
(Sp. 8-11.) 
Fl,-heads pedicellate, corymbose or subpaniculate (or terminal, solitary). 
Leaves tapering at base: 
Lys, lanceolate, acuminate, soon quite thi on 
both sides... ... ..- (8) speciosa. 
Lys. oblongo-lanceolate, white-woolly beneath... (9) Zeyheri. 
Leaves broad-based, lanceolate, thinly canous beneath, 
with revolute margins... .-. (10) Kirkii. 
Fl-heads sessile in the axils of the “uppermost leaves ; = ava. 
thinly canous beneath, tapering at base... ... (11) sessilifiora, 
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