Gottschling, M., and H. H.  Hilger. 2004. ?Characterisation of a novel fruit type found in Ehretia (Ehretiaceae, Boraginales)?. {BLUMEA} 49:145?153.

Gottschling, M., and H. H.  Hilger. 2003. ?First fossil record of transfer cells in angiosperms?. 90:957?959.

Gottschling, M., and H. H.  Hilger. 2001. ?Phylogenetic analysis and character evolution of Ehretia and Bourreria (Ehretiaceae, Boraginales) and their allies based on {ITS1} sequences?. 123:249?268.

Gottschling, M., N.  Diane, H. H.  Hilger, and M.  Weigend. 2004. ?Testing hypotheses on disjunctions present in the primarily woody Boraginales: Ehretiaceae, Cordiaceae, and Heliotropiaceae, inferred from ITS1 sequence data?. Int. J. Plant Sci. 165:S123?S135.

Diane, N., H. H.  Hilger, and M.  Gottschling. 2002. ?Transfer cells in the seeds of Boraginales?. Bot. J. Linn. Soc. 140:155?164.

Diane, N., C.  Jacob, and H. H.  Hilger. 2003. ?Leaf anatomy and foliar trichomes in Heliotropiaceae and their systematic relevance?. Flora 198:468?485.

Danin, A. 2000. ?The nomenclature news of Flora Palestina?. 10:109?172.

Clermont, A., E.  Zippel, and H. H.  Hilger. 2003. ?Verbreitung und Differenzierung der mitteleuropäischen Unterarten von Buglossoides arvensis (L.) I.M.Johnst. (Boraginaceae)?. Feddes Repert. 114:58?70.

Buys, M., and H. H.  Hilger. 2003. ?Boraginaceae cymes are exclusively scorpioid and not helicoid?. Taxon 52:719?724.

Briechle, M., and H. H.  Hilger. 1988. ?Die Embryogenese von Microparacaryum intermedium und die embryologische Klassifizierung der Boraginaceae nach Souèges?. Flora 181:45?59.

Böhle, U. - R., H. H.  Hilger, and W. F.  Martin. 1996. ?Island colonization and evolution of the insular woody habit in Echium L. (Boraginaceae)?. 93:11740?11745.

Hilger, H. H. 1986. ?Mikromorphologische Untersuchungen an Klausenoberflächen von Boraginaceae II. Mattiastrum (Boiss.) Brand (Cynoglosseae)?. 61:145?165.

Hilger, H. H., and U.  Richter. 1982. ?Untersuchungen zur Ausbildung der Klausen und ihrer Oberflächenskulpturen bei Paracaryum intermedium (Boraginaceae) aus Jordanien?. Beitr. Biol. Pflanzen 57:205?220.

Hilger, H. H., , and M.  Hofmann. 1993. ?Energiedispersive Röntgenmikroanalyse (EDX) von Boraginaceae subfam. Boraginoideae - Klausenoberflachen. Sind Silicium- und Calcium - Einlagerungen in die Fruchtwand systematisch verwertbare Merkmale??. Flora 188:387?398.

Hilger, H. H. et al. 2005. ?The {Euro+Med} treatment of Boraginaceae in Willdenowia 34 - a response?. Willdenowia 35:43?48.

Hilger, H. H., and H.  Förther. Submitted. ?Boraginaceae?. New York Botanical Garden Press.

Hilger, H. H., and N.  Diane. 2003. ?A systematic analysis of Heliotropiaceae (Boraginales) based on trnL and ITS1 sequence data?. Bot. Jahrb. Syst. 125:19?51.

Hilger, H. H., and U. R.  Böhle. 2000. ?Pontechium: a new genus distinct from Echium and Lobostemon (Boraginaceae)?. Taxon 49:737?746.

Hilger, H. H., M.  Balzer, W.  Frey, and D.  Podlech. 1985. ?Heteromerikarpie und Fruchtpolymorphismus bei Microparacaryum, gen. nov. (Boraginaceae)?. 148:291?312.

Hilger, H. H. 1994. ?Die Evolution der Rauhblattgewächse (Boraginaceae) in Makaronesien?. 8:23?32.

Hilger, H. H. 1992. ?Morphology of Heliotropium (Boraginaceae) dispersal units?. Bot. Acta 105:387?393.

Hilger, H. H. 1992. ?Diversität trotz starrer Form: die Klausen der Boraginaceae?. 157.

Hilger, H. H. 1989. ?Flower and fruit development in the Macaronesian endemic Ceballosia fruticosa (syn. Messerschmidia fruticosa, Boraginaceae, Heliotropioideae)?. 166:119?129.

Hilger, H. H. 1987. ?Fruchtbiologische Untersuchungen an Heliotropioideae (Boraginaceae). I. Die Ontogenie der monospermen Früchte von Heliotropium supinum L.?. Flora 179:291?303.

Hilger, H. H. 1987. ?Flower and fruit development in Wigandia caracasana (Hydrophyllaceae)?. 74:250?259.

Hilger, H. H. 1985. ?Ontogenie, Morphologie und systematische Bedeutung geflügelter und glochidientragender Cynoglosseae- und Eritrichieae-Früchte (Boraginaceae)?. Bot. Jahrb. Syst. 105:323?378.

Hilger, H. H. 1984. ?Wachstum und Ausbildungsformen des Gynoeceums von Rochelia (Boraginaceae)?. 146:123?139.

Hilger, H. H. 1981. ?Entwicklungstendenzen im Fruchtbau der anemochoren Boraginaceengattungen Mattiastrum und Paracaryum?. 94:677?687.

Hilger, H. H. 1981. ?Die Perikarpentwicklung geflügelter Klausen aus dem Paracaryum -Verwandtschaftskreis (Cynoglosseae, Boraginaceae)?. 138:73?88.

Gottschling, M., J. S.  Miller, M.  Weigend, and H. H.  Hilger. 2005. ?Congruence of a phylogeny of Cordiaceae (Boraginales) inferred from {ITS1} sequence data with morphology, ecology, and biogeography?. 92:425?437.

Gottschling, M., D. H.  Mai, and H. H.  Hilger. 2002. ?The systematic position of Ehretia fossils (Ehretiaceae, Boraginales) from the European Tertiary and implications for character evolution?. 121:149?156.

Gottschling, M., and H. H.  Hilger. 2004. ?The systematic position of Ehretia cortesia nom. nov. (= Cortesia cuneifolia: Ehretiaceae, Boraginales) inferred from molecular and morphological data?. Taxon 53:919?923.

Selvi, F., A.  Papini, H. H.  Hilger, M.  Bigazzi, and E.  Nardi. 2004. ?The phylogenetic relationships of Cynoglottis (Boraginaceae-Boragineae) inferred from {ITS}, {5.8S} and {trnL} sequences?. 246:195?209.

Selvi, F., M.  Bigazzi, H. H.  Hilger, and A.  Papini. 2006. ?Molecular phylogeny, morphology and taxonomic re-circumscription of the generic complex {Nonea/Elizaldia/Pulmonaria/Paraskevia} (Boraginaceae-Boragineae)?. 55:907?918.

Hilger, H. H., and E.  Zippel. 2001. ?{"Studies} in the Boraginaceae" - an index to the publications of Ivan M. Johnston dealing with the borage familiy?. 11:1?151.

Hilger, H. H., F.  Selvi, A.  Papini, and M.  Bigazzi. 2004. ?Molecular systematics of Boraginaceae tribe Boragineae based on {ITS1} and {trnL} sequences, with special reference to Anchusa s.l.?. 94:201?212.

Hilger, H. H., T. C. H.  Cole, and F.  Selvi. 2014. ?J.G.C. Lehmann's 'Botanical Observations' of 1818 on Coldenia, Colsmannia, Cynoglossum, and Omphalodes (commented translation)?. 2:e1064. Retrieved  (http://biodiversitydatajournal.com/articles.php?id=1064).

Hilger, H. H. 2014. ?Ontogeny, morphology, and systematic significance of glochidiate and winged fruits of Cynoglosseae and Eritrichieae (Boraginaceae)?. Plant diversity and evolution 131(3):167 - 214.

Greuter, W., V.  Stier, and H. H.  Hilger. 2014. ?Proposal to conserve the name Omphalodes verna against Omphalodes omphaloides (Boraginaceae)?. Taxon 63(2):435.