African yam bean (Sphenostylis stenocarpa Hochst ex. A. Rich.) Harms is an underutilized tropical African tuberous legume. It belongs to the class Magnoliopsida; order Fabales; family Fabaceae; subfamily Papilionoideaea; and genus Sphenostylis. There are seven species in the genus Sphenostylis (Potter and Doyle 1994). African yam bean (AYB) is the most valuable. The arable tuberous legume is important in most indigenous African food cultures and in peasant agriculture.
Descriptors for African yam bean, Sphenostylis stenocarpa (Hochst ex. A. Rich.) Harms. Genetic Resources Center, International Institute of Tropical Agriculture.
| Code | Term | Description |
|---|---|---|
| 0 | Absent | |
| 1 | Present |
Legend:
Slight
Moderate
Extensive
| Code | Term | Description |
|---|---|---|
| 0 | Absent | |
| 1 | Present |
Legend:
Slight
Moderate
Extensive
| Code | Term | Description |
|---|---|---|
| 0 | Absent | |
| 1 | Present |
Legend:
Slight
Moderate
Extensive
| Code | Term | Description |
|---|---|---|
| 0 | Non-shattering | |
| 1 | Shattering |
| Code | Term | Description |
|---|---|---|
| 0 | Absent | |
| 1 | Present |
| Code | Term | Description |
|---|---|---|
| 1 | Smooth | |
| 2 | Rough | |
| 3 | Wrinkled (folds on the testa |
| Code | Term | Description |
|---|---|---|
| 1 | Matt | |
| 2 | Medium | |
| 3 | Shiny |
| Code | Term | Description |
|---|---|---|
| 0 | Non?white seeds | |
| 1 | Clean (no color around the hilum) | |
| 3 | Brown | |
| 4 | Black |
| Code | Term | Description |
|---|---|---|
| 1 | Round/globular | |
| 2 | Oval | |
| 3 | Oblong | |
| 4 | Rhomboid |
| Code | Term | Description |
|---|---|---|
| 1 | White | |
| 2 | Grey | |
| 3 | Cream | |
| 4 | Light brown | |
| 5 | Reddish brown | |
| 6 | Dark brown | |
| 7 | Purple | |
| 8 | Variegated (mosaic) |