Rubus × 'APF-205T' (marketed as Stark Black Gem, Stark Black Jim or Midnight Jewel) is an upright, everbearing primocane blackberry developed by the University of Arkansas breeding program from a 2005 hand-pollinated cross. Its genetic heritage is derived from the hybridization of the female parent 'APF-77' and the male parent 'APF-49T'. This specific pairing aimed to blend multiple advanced traits: 'APF-77', known as 'Black Magic', provided strong foundational genetics for primocane (first-year cane) fruiting, while the unreleased genotype 'APF-49T' contributed crucial traits for enhanced productivity and improved berry presentation. The resulting hybrid surpassed both parents, yielding larger fruit and smoother, completely thornless canes compared to 'APF-77', while achieving higher vigor and far superior overall crop yields than 'APF-49T'.

The fruit of 'Midnight Jewel' is noted for its ovate shape, glossy black appearance, and a exceptionally soft, melting internal core receptacle. Cultivated for premium fresh eating, it expresses a high sugar profile of 11% to 12% soluble solids coupled with significantly lower titratable acidity than standard commercial blackberries, removing the sharp tartness typically found in older varieties. Midnight Jewel is considered a home-gardener variety rather than a commercial-grade blackberry as it lacks the firmness, yield consistency, and shelf-life required by large-scale commercial farming and grocery supply chains. Because it produces fruit on both second-year floricanes in mid-summer and first-year primocanes from August until frost, it represents a key advancement in extending the seasonal availability of functional antioxidants in home gardens and specialty markets.