I. ACKNOWLEDCEMENTS ......................................... 5
II. INTRODUCTION ............................................. 6
III. DISTRIBUTION ............................................. 7
IV. CHECKLIST OF ENDANCERED SPECIES (UPDATE 1005) ............ 8
V. OVERVIEW OF THE TAXONOMY OF THE GENUS SCLEROCACTUS
BRITTON & ROSE ........................................... 8
KEY OF THE GENUS SCLEROCACTUS ............................ 9
VI. SCLEROCACTUS BRITTON & ROSE ............................. 11
6.1 SECTION MESAE-VERDAE HOCHSTÄTTER .................... 12
Key to the Section Mesae-Verdae ..................... 12
Sclerocactus mesae-verdae (Boissevain & Davidson)
L. Benson ........................................... 13
Sclerocactus wetlandicus Hochstätter ssp.
wetlandicus ......................................... 15
Sclerocactus wetlandicus Hochstätter ssp.
ilseae Hochstätter .................................. 17
6.2 SECTION PARVIFLORI HOCHSTäTTER ...................... 19
Key to the Section Parviflori ....................... 19
Scierocactus parviflorus Clover & Jotter ssp.
parviflorus ......................................... 21
Scierocactus parviflorus Clover & Jotter ssp.
havasupaiensis (Clover) Hochstätter ................. 23
Scierocactus parviflorus Clover & Jotter ssp.
terrae-canyonae (Heil) Heil & Porter ................ 25
Scierocactus parviflorus Clover & Jotter ssp.
macrospermus Hochstätter ............................ 27
Scierocactus parviflorus Clover & Jotter ssp.
variiflorus Hochstätter ............................. 29
Scierocactus whipplei (Engelmann & Bigelow)
Britton & Rose ssp. whipplei ........................ 31
Scierocactus whipplei (Engelmann & Bigelow)
Britton & Rose ssp. busekii Hochstätter ............. 33
Scierocactus whipplei (Engelmann & Bigelow)
Britton & Rose subv. aztecia Hochstätter ............ 35
Scierocactus glaucus (Purpus ex Schumann)
L. Benson ........................................... 37
Scierocactus wrightiae L. Benson .................... 39
6.3 SECTION SCLEROCACTUS HOCHSTäTTER .................... 41
Key to the Section Sclerocactus ..................... 41
Sclerocactus polyancistrus (Engelmann & Bigelow)
Britton & Rose ...................................... 42
Sclerocactus nyensis Hochstätter .................... 45
Sclerocactus pubispinus (Engelmann) L. Benson ....... 47
Sclerocactus spinosior (Engelmann) Woodruff &
L. Benson ssp. spinosior ............................ 50
Sclerocactus spinosior (Engelmann) Woodruff &
L. Benson ssp. blainei .............................. 52
(Welsh & Thorne) Hochstätter
6.4 SCLEROCACTUS SPEC ................................... 53
VII. ISOENZYME ANALYSIS OF SCLEROCACTUS AND RELATED GENERA
by M. Konnert ........................................... 54
VIII. SUMMARY OF STUDIES OF SCLEROCACTUS SEED MORPHOLOGY
by G. Hentzschel ........................................ 57
IX. SCANNING ELECTRON MICROCRAPHS OF SEEDS
by C.R.W. Frank ......................................... 59
X. CULTIVATION ............................................. 64
Winterhardy List of the Genus Sclerocactus .............. 64
Climatic Data ........................................... 65
XI. PICTURES AND ILLUSTRATIONS .............................. 67
11.1 Index of Pictures and lllustrations ................ 68
11.2 Picture Credits .................................... 78
11.3 Pictures of Sclerocactus ........................... 79
11.4 Sclerocactus spec ................................. 223
11.5 Pictures of Cultivation ........................... 237
11.6 Distribution Maps ................................. 247
11.7 Cross-Sections of Flowers ......................... 254
11.8 Original First Descriptions ....................... 257
XII. DEUTSCHE ZUSAMMENFASSUNG - GERMAN SUMMARY .............. 291
12.1 Danksagung ........................................ 292
12.2 Einleitung ........................................ 292
12.3 Checkliste der gefährdeten Spezies der Gattung
Sclerocactus (update 2005) ........................ 293
12.4 Übersicht der Taxonomie der Gattung Sclerocactus
Britton & Rose .................................... 294
12.5 Sclerocactus Britton & Rose ....................... 296
Sektion Mesae-Verdae Hochstätter .................. 296
Sektion Parviflori Hochstätter .................... 299
Sektion Scierocactus Hochstätter .................. 308
12.6 Zusammenfassung der morphologischen
Untersuchungen der Samen von Sclerocactus von
G. Hentzschel ..................................... 313
12.7 Isoenzymanalysen von Sclerocactus und verwandten
Gattungen von M. Konnert .......................... 314
12.8 Kultivierung ...................................... 316
XIII. GLOSSARY ............................................... 317
XIV. BIBLIOGRAPHY ........................................... 327
XV. ABBREVIATIONS OF HERBARIA REFERENCES ................... 330
XVI. fh - FIELDNUMBERS (UPDATE 2005) ........................ 331
XVII. INDEX OF SCIENTIFIC NAMES .............................. 333
XVIII. INDEX OF COMMON NAMES .................................. 334
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