86. B alsamorhiza. Rays numerous. Pappus none. Receptacle flat.
87. H eu o p s is . Rays 10-15. Pappus none. Receptacle conical.
88. T etragonotiieca. Rays 6-9. Pappus none. Scales of the exterior involucre
4, foliaceous, united towards the base.
89. H alea. Rays 6-12. Pappus of numerous distinct, small and rigid scales.
Exterior involucre of 4-5 foliaceous scales united below.
Div. 2. EuHELiANTHEai.—Rays sterile. Achenia never obcompressed.
* Pappus coroniform, somewhat %-toothed, or none.
+- Receptacle conical or columnar.
90. E chinacea. Achenia quadrangular. Chaff* with a cartilaginous cusp.
91. R udbeckia. Achenia quadrangular. Chaff* navicular or concave.
92. L epachys. Achenia compressed, somewhat 1-2-winged, 1-2-toothed. Chaff*
truncate.
93. D raco-p is . Achenia terete. Chaff linear.
■*- +- Receptacle flat or convex.
94. G ymnopsis. Pappus coroniform. Achenia enclosed in the chaff.
95. E ncelia. Pappus none. Margins of the compressed achenia villous.
* * Pappas aristiform or squamelliform.
96. V iguiera. Pappus of 4 squamellce and 2 awns. Involucre scarcely imbricated.
. J
97. H elianthus. Pappus of 2 chaffy awns and often 2-4 squamellse, caducous.
Involucre imbricated. Achenia wingless.
98. H euan th ei/ea. Pappus lacerate-toothed or slightly winged or margined. awned,at the angles. Achenia
99. A ctinomekis. Pappus of 2 persistent awns. Achenia winged.
Div. 3. Coreofsideas. Rays sterile. Achenia obcompressed, not rostrate. Awns
not retrorsely hispid.
100. A oarista. Achenia villous. Pappus of 2 long chaffy scales.
101. C oreopsis. Achenia mostly glabrous.
Div. 4. B identideje.—Rays sterile. Achenia either obcompressed or rostrate.
Awns retrorsely hispid.
102. Cosmos. Achenia rostrate. Awns deciduous. Chaff* slender.
103.. Qosmidujm. Achenia not rostrate. Awns persistent. Chaff short and obtuse.
Disk-corolla deeply cleft.
104. Bidens. Achenia rostrate or erostrate. Awns persistent. Disk-corolla
5-toothed.
Div. 5. V erbesineie. Rays fertile, rarely rnone. Achenia mostly compressed or
obcompressed, with a thin exterior integument.
* Achenia a!Z obcompressed. Dish-corolla with a barbellate ring. Involucre double.
105. L eptosyne. Pappus minute and cup-shaped. Rays 8-15.
1,06. T uckermannia. Pappus none. Rays 15-20.
* * Achenia, at least those of the dish, compressed.
107. S pilanthes. Receptacle conical. Appendages of the style truncate. Rays
deciduous, often none.
108. L ipochieta. Receptacle flattish. Achenia awned from the angles, and with
chaffy or squamellate teeth between the aWns.
109. Verbesina. Receptacle flattish. Achenia 2-awned. Rays few or none.
110. Ximenesia. Receptacle convex. Achenia of the disk 2-awned and winged,
of the ray wingless. Rays numerous. ’
111. Sanvitalia. Receptacle convex. Achenia of the ray 3-sided and 3-awned,
of the disk compressed, scarcely awned. Rays persistent.
Div. ®| H e i io e s id e « , DC.—Rays pistillate and fertile (in Melan-
thera none), ligulate. Achenia never obcompressed (that is, flattened) parallel
with the scales of the involucre or chaff of the receptacle; the exterior
integument (calyx-tube) thick and firm, often separable from the interior.
Pappus none, or coroniform, frequently toothed or with one or more rigid
awns.
83. MEL ANTHER A. “ Rohr, in Kiob. vat. hist, selslc. 2. (1792) p.
213” ;* Cass., in jour. phys. 1823, DC. prodr. 5. p . 544.
• Melananthera, Michx. tf-c.
Heads discoid, many-flowered; the flowers all tubular and perfect. Scales
of the involucre in a double series, nearly equal. Receptacle convex; the
persistent chaff partly sheathing the flowers. Teeth of the corolla papillose.
Branches of the style hispid above, acuminate. Achenia short, compressed-
quadrangular, or sometimes triangular, truncate at the summit. Pappus of
2 - 18 rather rigid scabrous caducous bristles or awns.—Perennial herbaceous
or rarely suffrutescent (American, tropical) scabrous plants, with quadrangular
branching stems. Leaves opposite, or rarely ternately verticillate, pe-
tioled, triplinerved, toothed or serrate, often 3-lobed. Heads ternate or solitary,
peduncled. Corolla white. Anthers black with whitish appendages.
1. M. hastata (Michx.): leaves opposite, very scabrous, mostly hastate-
3- lobed ; scales of the involucre lanceolate; chaff of the receptacle acuminate
cuspidate ; awns of the pappus 2-3.—DC. ! prodr. 5. p. 545. M. tri-
lobata & pandurseformis, Cass, in diet. 1. c. 29, p. 485. Melananthera hastata,
Michx.! Jl. 2. p. 107 ; Pursh! fi.. 2. p. 519; Ell. stc. 2. p. 315.
Bidens nivea, /3. & y. Linn, (ex syn. Dill. Elth. t. 49 ^*47); Walt. Car.
p. 201 ? Athanasia hastata, Walt.! 1. c.
Dry soil, S. Carolina! to Florida! and Louisiana! (Also in Cuba, La
Sagra, ex DC.) July-Sept.—Stem 4-6 feet high, often beautifully marbled
or spotted. Leaves variable in form, between lanceolate and deltoid-ovate,
either deeply or slightly hastate-3-lobed, or somewhat pandurifbrm, sometimes
undivided, acute or acuminate. Epigynous disk or nectary rather conspicuous,
sheathing the base of the style.
Transactions of the Natural History Society of Copenhagen.
von. ii.—38