Gueldenstaedtia verna (Georgi) Boriss., a rare legume species native to limited parts of Korea, was studied to investigate its seed dormancy type and optimal conditions for its germination. Morphological and anatomical observations confirmed that the seeds possess a fully developed foliate-bent embryo and a hard, colliculate yellow seed coat. Water imbibition tests showed only a 5.1 ± 2.6% increase in seed weight after 72 h, indicating the occurrence of physical dormancy due to an impermeable seed coat. No germination occurred under any constant or alternating temperature regimes (4, 15/6, 20/10, or 25/15°C) in non-scarified seeds, nor under two seasonal simulation regimes (Move A: from winter to summer; Move B: from summer to winter). However, scarification of seeds (using sandpaper, a needle prick [0.1 mm depth], or sulfuric acid) significantly improved germination. Seeds scarified with sandpaper or a needle prick achieved 100% germination within 1 week at 25/15°C, while sulfuric acid treatments (5 and 10 min) resulted in germination rates of 13.3% and 58.3%, respectively. These results confirm that G. verna seeds exhibit physical dormancy only and require scarification for immediate germination, with relatively high temperatures (25/15°C) being most effective. These findings deepen our understanding of the seed ecology of this rare species and provide useful insights for its conservation and potential horticultural application.