The Manual of the Botany of the Northern United States Part 84

Scales of the involucre in two rows. Leaves opposite 74

Scales of the involucre imbricated. Leaves alternate 10, 11, 15, 17, 35

[*] 2. Pappus a circle of awns or rigid bristles (at least in the disk).

Ray yellow, awns few (2--8) 12

Ray rose-color 23

[*] 3. Pappus a circle of chaffy scales, dissected into bristles 65

[*] 4. Pappus a circle of thin chaffy scales or short chaffy bristles.

Heads several-flowered. Receptacle chaffy 60

Heads 8--10-flowered. Receptacle naked 18

Heads many-flowered. Receptacle deeply honeycombed 58

Heads many-flowered. Receptacle naked 62, 63

Heads many-flowered. Receptacle chaffy 64

[*] 5. Pappus none, or a cup or crown, or of 2 or 3 awns, teeth, or chaffy scales corresponding with the edges or angles of the achene, often with intervening minute bristles or scales.

[+] Receptacle naked.

Achene flat, wing-margined. Pappus of separate little bristles and usually 2--4 awns 22

Achene flat, marginless. Pappus none. Receptacle conical 19

Achene terete or angled. Pappus none. Receptacle flattish 69

Achene angled. Pappus a little cup or crown (or none). Receptacle conical 20, 68

Achene fusiform. Pappus of few scales, usually with alternating awns 21

[+][+] Receptacle chaffy.

Rays neutral (rarely pistillate but sterile); the disk-flowers perfect and fertile.

Receptacle mostly elevated (varying from convex to columnar), and

Chaffy only at the summit; the chaff deciduous. Pappus none 66

Chaffy throughout. Achene flattened laterally if at all 48, 49, 50, 52, 54

Receptacle flat or flattish. Achene flattened, parallel with the scales or chaff 55, 56

Receptacle flat. Achene terete, 2-awned 57

Rays pistillate and fertile; the disk-flowers also perfect and fertile.

Achene much flattened laterally, 1--2-awned 53

Achene flattened parallel with the scales and chaff. Pappus none 67

Achene 3--4-angular, terete or laterally flattish, awnless.

Receptacle convex or conical. Leaves alternate, dissected 66

Receptacle conical. Leaves opposite, simple.

Achene obovoid. Involucre a leafy cup 45

Achene 4-angular. Involucre of separate scales 47

Receptacle flat. Leaves opposite and simple 46, 51

Rays pistillate and fertile; the disk-flowers staminate and sterile (pistil imperfect).

Receptacle chaffy 36-41

1. ELEPHaNTOPUS, L. ELEPHANT'S-FOOT.

Heads discoid, 2--5-flowered, several together cl.u.s.tered into a compound pedunculate head; flowers perfect. Involucre narrow, flattened, of 8 oblong dry scales. Achenes 10-ribbed; pappus of stout bristles, chaffy-dilated at the base.--Perennials, with alternate leaves and purplish flowers. (Name composed of ??efa?, _elephant_, and p???, _foot_.)

[*] _Stem leafy; upper leaves very like the basal._

1. E. Carolinia.n.u.s, Willd. Somewhat hairy, corymbose, leafy; leaves ovate-oblong, thin.--Dry soil, Penn. to Ill. and Kan., and southward.

[*][*] _Stem scape-like, with a few bract-like leaves or naked._

2. E. tomentsus, L. Somewhat hairy; basal leaves obovate to narrowly spatulate, silky and prominently veined beneath; heads large; pappus-scales attenuate.--Va., Ky., and southward.

3. E. nudatus, Gray. Strigose-p.u.b.erulent; basal leaves thin, green, spatulate-obovate or oblanceolate, not prominently veined beneath; heads smaller; pappus scales broadly deltoid.--Del. and southward.

2. VERNNIA, Schreb. IRON-WEED.

Heads discoid, 15--many-flowered, in corymbose cymes; flowers perfect.

Involucre shorter than the flowers, of many much imbricated scales.

Receptacle naked. Achenes cylindrical, ribbed; pappus double, the outer of minute scale-like bristles, the inner of copious capillary bristles.--Perennial herbs, with leafy stems, alternate and ac.u.minate or very acute leaves and mostly purple flowers. Species very difficult.

(Named for _Wm. Vernon_, an early English botanist who travelled in this country.)

[*] _Heads large, 50--70-flowered._