We continue with this series of publications on the flora of the province of Soria (NC Spain), which are previous to the review and reedition of the Floristic Catalogue of Soria (SEGURA & al., 2000), to incorporate 58 taxa corresponding to vascular plants, fifty of which had not previously been recorded for the flora of this province. Since the level of prospection in the province is currently very high, these most recent findings correspond to rare and scarce taxa in the province?s territorial context; some of them are peripheral or very localized, whereas others are restricted to environments that are both scarce and well preserved; in general, all of them show a presence extent very diffuse or fragmented in the province. Another part are recently described taxa of a sub specific rank. All of them provide with an enlargement of their known distribution area, or with an improvement in their demarcation. Some floristic rarities and some regional novelties stand out, such as Apera spica-venti, Biscutella atropurpurea, Blackstonia perfoliata subsp. intermedia, Centaurea nevadensis, Crepis alpina, Crepis sancta y Puccinellia caespitosa, besides other species that are very scarce, peripheral, relict or showing a fragmented area of distribution in the Province, such as Astragalus glaux, Cardamine parviflora, Crocus nevadensis, Euphrasia officinalis, Orobanche leptantha, Rosa elliptica, Rosa glauca, Trifolium diffusum, or Leucanthemopsis cuneata subsp. valdes-bermejoi.