The best known member is the herb Fenugreek.
The genus Trigonella currently has 37 recognized species:
Trigonella anguina Delile
Trigonella arabica Delile
Trigonella balansae Boiss. & Reut.
Trigonella berythea Boiss. & Blanche
Trigonella bicolor (Boiss. & Balansa) Lassen
Trigonella caerulea (L.) Ser., blue fenugreek
Trigonella calliceras Fisch. ex M. Bieb.
Trigonella coelesyriaca Boiss.
Trigonella coerulescens (M. Bieb.) Hal.
Trigonella corniculata (L.) L., cultivated fenugreek
Trigonella cretica (L.) Boiss.
Trigonella cylindracea Desv.
Trigonella elliptica Boiss.
Trigonella emodi Benth.
Trigonella foenum-graecum L., sicklefruit fenugreek
Trigonella geminiflora Bunge
Trigonella glabra Thunb.
Trigonella gladiata Steven ex M. Bieb.
Trigonella gracilis Benth.
Trigonella grandiflora Bunge
Trigonella hierosolymitana Boiss., branched fenugreek
Trigonella kotschyi Boiss.
Trigonella laxiflora Aitch. & Baker
Trigonella macrorrhyncha Boiss.
Trigonella maritima Delile ex Poir.
Trigonella mesopotamica Hub.-Mor.
Trigonella occulta Ser.
Trigonella procumbens (Besser) Rchb., trailing fenugreek
Trigonella rechingeri Širj.
Trigonella schlumbergeri Boiss.
Trigonella spicata Sm.
Trigonella spinosa L.
Trigonella spruneriana Boiss.
Trigonella stellata Forssk.
Trigonella suavissima Lindl.
Trigonella velutina Boiss.
Trigonella verae Širj.