¹"Granum sinapis" is Latin for ‘mustard seed.’
²Letter to Odo of Soissons, Magister Theologus at Paris (Epistola CXXVII in: Migne, J.P., Patrologia Latina, S. Hildegardis abbatissae opera omnia, Tom. 197, 352C):  "Nunc audi: Rex in solio suo sedit, et magnas columnas et valde elegantes in magnis ornamentis coram se statuit, quae sunt ornamenta eboris erecta sunt, et quae omnia indumenta regis in magnis honoribus gestabant. Tunc Regi placuit, et parvam pennam de terra levavit, et illi praecepit ut volaret, sicut idem rex voluit. Penna autem e seipsa non volat, sed aer eam portat. Sic ego non sum imbuta humana doctrina, nec potentibus viribus, nec etiam aestuo in sanitate corporis, sed in adjutorio Dei consisto."
³St. Boniface (c.673—754), whose Anglo-Saxon name was Winfred, was an English Benedictine monk and missionary in Frisia, Hesse, Thuringia, and Bavaria.  He is the founder of numerous monasteries and bishoprics, e.g.  the monasteries of Fritzlar, Tauberbischofsheim, and Fulda, as well as the bishoprics of Freising, Passau, Regensburg, Erfurt, Würzburg, and Eichstätt.  To this day he is known as the «Apostel der Deutschen».
⁴See footnote 14, p. 521
⁵It is interesting to note that manuscript W (Würzburger Handschrift) has "smekender", which is reminiscent of Hildegard’s four ways to experience the mystical:  through visions, smell,  aste, and touch.