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

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

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.

Weigend, M., M.  Gottschling, F.  Selvi, and H. H.  Hilger. 2010. ?Fossil and extant Western Hemisphere Boragineae, and the polyphyly of "Trigonotideae" Riedl (Boraginaceae: Boraginoideae)?. Systematic Botany 35(2):409 - 419. Retrieved  (http://www.bioone.org/doi/abs/10.1600/036364410X518874).

Weigend, M., M.  Gottschling, H. H.  Hilger, and N. M.  Nürk. 2010. ?Five new species of Lithospermum L. (Boraginaceae tribe Lithospermeae) in Andean South America: Another radiation in the Amotape-Huancabamba zone?. Taxon 59(4):1161 - 1179. Retrieved  (http://www.ingentaconnect.com/content/iapt/tax/2010/00000059/00000004/art00015).

Weigend, M., and H. H.  Hilger. 2010. ?Codonaceae ? a newly required family name in Boraginales?. Phytotaxa 10:26 - 30.

Weigend, M., M.  Gottschling, F.  Selvi, and H. H.  Hilger. 2009. ?Marbleseeds are gromwells - Systematics and evolution of Lithospermum and allies (Boraginaceae tribe Lithospermeae) based on molecular and morphological data?. Molecular Phylogenetics and Evolution 52(3):755 - 768. Retrieved  (http://www.sciencedirect.com/science/article/B6WNH-4WBK7BK-3/2/5ef424fa3684d5c985634011154460d5).

Thomas, D. C., M.  Weigend, and H. H.  Hilger. 2008. ?Phylogeny and systematics of Lithodora (Boraginaceae-Lithospermeae) and its affinities to the monotypic genera Mairetis, Halacsya and   Paramoltkia based on ITS1 and trnL(UAA)-sequence data and morphology?. Taxon 57(1):79 - 97.

Luebert, F., P.  Jacobs, H. H.  Hilger, and L. A. H.  Muller. 2014. ?Evidence for nonallopatric speciation among closely related sympatric Heliotropium species in the Atacama Desert?. Ecology and Evolution 4(3):266 - 275. Retrieved  (http://onlinelibrary.wiley.com/doi/10.1002/ece3.929/abstract).

Weigend, M., F.  Luebert, F.  Selvi, G.  Brokamp, and H. H.  Hilger. 2013. ?Multiple origins for Hound?s tongues (Cynoglossum L.) and Navel seeds (Omphalodes Mill.) ? The phylogeny of the borage family (Boraginaceae s.str.)?. Molecular Phylogenetics and Evolution 68(3):604 - 618. Retrieved  (http://www.sciencedirect.com/science/article/pii/S1055790313001590).

Luebert, F., H. H.  Hilger, and M.  Weigend. 2011. ?Diversification in the Andes: Age and origins of South American Heliotropium lineages (Heliotropiaceae, Boraginales)?. Molecular Phylogenetics and Evolution 61(1):90 - 102. Retrieved  (http://dx.doi.org/10.1016/j.ympev.2011.06.001).

Luebert, F., G.  Brokamp, J.  Wen, M.  Weigend, and H. H.  Hilger. 2011. ?Phylogenetic relationships and morphological diversity in Neotropical Heliotropium (Heliotropiaceae)?. Taxon 60(3):663 - 680. Retrieved  (http://www.ingentaconnect.com/content/iapt/tax/2011/00000060/00000003/art00004).

Luebert, F., M.  Weigend, and H. H.  Hilger. 2010. ?Epitypification of Heliotropium arborescens L. (Heliotropiaceae)?. Taxon 59(4):1263 - 1266. Retrieved  (http://www.ingentaconnect.com/content/iapt/tax/2010/00000059/00000004/art00023).

Gottschling, M., F.  Luebert, H. H.  Hilger, and J. S.  Miller. 2014. ?Molecular delimitations in the Ehretiaceae (Boraginales)?. Molecular Phylogenetics and Evolution 72:1 - 6. Retrieved  (http://www.sciencedirect.com/science/article/pii/S1055790313004405).

Weigend, M. et al. 2014. ?From capsules to nutlets ? Phylogenetic relationships in the Boraginales?. Cladistics 30(5):508-518. Retrieved  (http://onlinelibrary.wiley.com/doi/10.1111/cla.12061/abstract).