The Manual of the Botany of the Northern United States - LightNovelsOnl.com
You're reading novel online at LightNovelsOnl.com. Please use the follow button to get notifications about your favorite novels and its latest chapters so you can come back anytime and won't miss anything.
[+] Heads rather large, pedunculate, radiate or rarely rayless.
68. Matricaria. Receptacle conical. Rays pistillate or none. Pappus crown-like or none.
69. Chrysanthemum. Receptacle flattish. Rays many, pistillate. Pappus none.
[+][+] Heads mostly small, discoid, corymbed or paniculate.
70. Tanacetum. Heads corymbed. Achene with broad summit; pappus a short crown.
71. Artemisia. Heads in panicled spikes or racemes. Achenes with narrow summit; pappus none.
Tribe VIII. SENECIONIDEae. Heads radiate or discoid, the involucre little or not at all imbricated, not scarious. Receptacle naked. Anthers tailless. Pappus capillary.
[*] Heads moncious or subdicious, the perfect flowers mostly sterile, and the small (ligulate or tubular) ray-flowers in more than one row (at least in the fertile heads). Style-branches obtuse, not appendaged nor hispid. Leaves all radical.
72. Tussilago. Head solitary, yellow-flowered, moncious.
73. Petasites. Heads corymbed, subdicious. Flowers white or purplish.
[*][*] Flowers all fertile. Style-branches truncate or capitellate, often appendaged. Involucral scales connivent-erect.
[+] Leaves opposite.
74. Arnica. Heads showy. Pappus rather rigid, scabrous.
[+][+] Leaves alternate. Pappus soft-capillary, copious.
75. Senecio. Heads usually radiate. Corollas yellow, 5-toothed.
76. Cacalia. Heads discoid. Corollas white or cream-colored, 5-cleft.
77. Erecht.i.tes. Heads discoid. Flowers whitish, the outer pistillate with filiform corollas.
Tribe IX. CYNAROIDEae. Flowers all tubular and perfect (the outer ray-like and neutral in n. 82). Involucre much imbricated. Anthers caudate, long-appendaged at tip. Style-branches short or united, obtuse, unappendaged, smooth, with often a p.u.b.escent ring below. Pappus mostly bristly.--Leaves alternate.
[*] Achenes attached by the base. Flowers all alike.
[+] Leaves not p.r.i.c.kly. Style-branches partly distinct. Filaments glabrous.
78. Arctium. Involucral scales hooked at the tip. Pappus of short rough bristles.
[+][+] Leaves p.r.i.c.kly. Style-branches coherent, usually a p.u.b.escent ring below.
79. Cnicus. Pappus bristles plumose. Receptacle densely bristly.
80. Carduus. Pappus-bristles not plumose. Receptacle densely bristly.
81. Onopordon. Pappus-bristles not plumose. Receptacle deeply honeycombed.
[*][*] Achenes attached obliquely. Marginal flowers often enlarged and ray-like.
82. Centaurea. Involucral scales appendaged. Pappus double and bristly, or very short or none.
SERIES II. LIGULIFLORae. Tribe X. CICHORIACEae.
Corolla ligulate in all the flowers of the head, and all the flowers perfect.--Herbs, with milky juice. Leaves alternate.
[*] Pappus none.
83. Lampsana. Involucre cylindrical, of 8 scales in a single row, 8--12-flowered.
[*][*] Pappus chaffy, or of both chaff and bristles.
84. Krigia. Involucre simple, not calyculate. Pappus of both chaff and bristles.
85. Cichorium. Involucre double. Pappus a small crown of many bristle-form scales.
[*][*][*] Pappus plumose.
86. Tragopogon. Involucre simple, not calyculate. Achenes long-beaked.
Stems leafy.
87. Leontodon. Involucre calyculate. Achenes fusiform. Leaves radical.
88. Picris. Outer involucral scales spreading. Achenes terete. Stems leafy.
[*][*][*][*] Pappus composed entirely of capillary bristles, not plumose.
[+] Achenes not flattened, columnar or terete, often slender.
[++] Achenes not beaked.
[=] Flowers yellow or orange.
89. Hieracium. Involucre imbricated. Pappus tawny. Pilose perennials.
90. Crepis. Involucral scales in one row. Pappus white, soft. Not pilose.
[=][=] Flowers white or cream color or pinkish. Involucre calyculate.
91. Prenanthes. Achenes short, blunt. Pappus tawny or brown. Stems leafy and heads often nodding.
92. LyG.o.desmia. Achenes long, tapering. Pappus white. Stems nearly leafless; heads erect. Western.
[++][++] Achenes beaked (sometimes beakless in n. 93). Flowers yellow.
93. Troximon. Scapose. Involucre loosely imbricated. Achenes 10-ribbed.
94. Taraxac.u.m. Scapose. Involucre calyculate. Achenes 4--5-ribbed.
