| Phylogeny of Apocynoideae and the Apsa clade (Apocynaceae SL) 1 T Livshultz, DJ Middleton, ME Endress, JK Williams Annals of the Missouri Botanical Garden 94 (2), 324-359, 2007 | 130 | 2007 |
| Anatomía y densidad o peso específico de la madera JLH Williams Revista Forestal Venezolana 54 (1), 67-76, 2010 | 55 | 2010 |
| Anatomía de madera en 31 especies de la subfamilia Mimosoideae (Leguminosae) en Venezuela H León, J Williams Colombia forestal 11 (1), 113-135, 2008 | 32 | 2008 |
| The Mexican genera of the Apocynaceae (sensu A. DC.), with key and additional taxonomic notes JK WILLIAMS SIDA, Contributions to Botany, 197-213, 1996 | 25 | 1996 |
| Allotoonia, a new neotropical genus of Apocynaceae based on a subgeneric segregate of Echites JF Morales, JK Williams SIDA, Contributions to Botany, 133-158, 2004 | 23 | 2004 |
| A revision of Thenardia HBK (Apocynaceae, Apocynoideae) JK Williams Lundellia 1998 (1), 78-94, 1998 | 21 | 1998 |
| Thoreauea (Apocynaceae: Apocynoideae), a new genus from Oaxaca, Mexico JK Williams Lundellia 2002 (5), 47-58, 2002 | 19 | 2002 |
| A phylogenetic and taxonomic study of the Apocynaceae subfamily Apocynoideae of Mexico with synopsis of subfamily Plumerioideae JK Williams The University of Texas at Austin, 1999 | 16 | 1999 |
| Species-area relationships indicate large-scale data gaps in herbarium collections JK Williams, WL Lutterschmidt Lundellia 2006 (9), 41-50, 2006 | 14 | 2006 |
| POLYPHYLY OF THE GENUS ECHUES (APOCYNACEAE: APOCYNOIDEAE: ECHITEAE): EVIDENCE BASED ON A MORPHOLOGICAL CLADISTIC ANALYSIS JK Williams SIDA, Contributions to Botany, 117-131, 2004 | 14 | 2004 |
| A further evaluation of Echites sect. Yucatanense (Apocynaceae) with additional notes on the genus JK Williams Brittonia 54 (4), 310-317, 2002 | 14 | 2002 |
| Additions to the alien vascular flora of Mexico, with comments on the shared species of Texas, Mexico, and Belize JK Williams Phytoneuron 3, 1-7, 2010 | 11 | 2010 |
| A NEW COMBINATION IN" THEVETIA"(APOCYNACEAE) JK WILLIAMS SIDA, Contributions to Botany, 185-190, 1996 | 11 | 1996 |
| Miscellaneous notes on Haplophyton (Apocynaceae: Plumerieae: Haplophytinae) JK WILLIAMS SIDA, Contributions to Botany, 469-475, 1995 | 10 | 1995 |
| Analysis of the modern distribution of South African Gerbilliscus (Rodentia : Gerbillinae) with implications for Plio-Pleistocene palaeoenvironmental reconstruction TL Campbell, PJ Lewis, JK Williams South African Journal of Science 107 (1), 1-8, 2011 | 9 | 2011 |
| Anatomía de la madera de 17 especies de la familia Malpighiaceae Juss H León, J Williams Acta Científica Venezoelana 57 (2), 49-58, 2006 | 9 | 2006 |
| Una nueva combinación en el género Allotoonia (Apocynaceae, Apocynoideae, Echiteae) F Morales, J Williams Lankesteriana 5 (2), 2005 | 8 | 2005 |
| A new species of Tintinnabularia (Apocynaceae, Apocynoideae) from Honduras, with taxonomic notes JK Williams Lundellia 1999 (2), 136-141, 1999 | 8 | 1999 |
| A new combination in Mexican Mandevilla (Apocynaceae) J WILLIAMS SIDA, Contributions to Botany, 237-239, 1998 | 8 | 1998 |
| Analysis of the completeness of vascular plant records in Florida JK Williams, A Debelica Journal of the Botanical Research Institute of Texas, 1363-1371, 2008 | 7 | 2008 |
