Trifolium (Clovers) of California's Boletim

Some hints for a proper distinction of tomcat clover (Trifolium willdenovii) and white-tipped clover (Trifolium variegatum):
1) The main diagnostic feature in the Jepson key is the shape of the calyx teeth and the proportions of calyx teeth and calyx tube. The teeth of white-tipped clover are as long as or longer than the calyx tube, and the teeth are gradually tapered (see e.g. https://www.inaturalist.org/observations/144582186 or https://inaturalist-open-data.s3.amazonaws.com/photos/136148394/original.jpg). The teeth of tomcat clover are shorter than the calyx tube and almost always shouldered below the tapered tip (see e.g. https://inaturalist-open-data.s3.amazonaws.com/photos/208385679/original.jpeg or https://www.inaturalist.org/observations/119145286 or https://www.inaturalist.org/observations/117409172). This most important diagnostic feature is often (but not always) visible on the photos.
2) The second diagnostic feature in the Jepson key (tomcat clover: calyx tube splitting between upper lobes; white-tipped clover: calyx tube NOT splitting between upper lobes) is mostly hard to see.
3) But the shape and the color of the corolla are very good first hints. The corolla of the tomcat clover is longer, more slender and that of the white-tipped clover shorter, a little bit more stocky. The color of the upper part of the banner of tomcat clover is light purple or lavender, and the shape is more quadratic (not that long-stretched) (see e.g. https://www.inaturalist.org/observations/117249352). The color of the upper part of the banner of white-tipped clover is normally white, so the contrast of the coloring of the lower and upper part of the corolla is much more distinct. The shape of the upper part of the corolla of the white-tipped clover is more rectangular (long-stretched) (see e.g. https://www.inaturalist.org/observations/114793704).
4) The inflorescence of tomcat clover is normally broader and more like a ‘W’ and that of white-tipped clover almost always narrower and more like a ‘V’. But both species are annual (or short-lived), so the variability of the size of the inflorescences is extreme.
5) Also the shape of the leaflets is generally different, but a transitional zone exists: the leaflets of tomcat clover are linear (e.g. https://www.inaturalist.org/observations/146909524) to narrow obovate (almost always much longer than broad) and that of the white-tipped clover broad obovate (not much longer than broad) (e.g. https://www.inaturalist.org/observations/117226954).
6) Not really mentioned in Jepson is the shape of the upper stipules, but I think this is almost always a very good diagnostic feature. The upper stipules of white-tipped clover are deeply and quite regularly incised, and, very important, they are normally and typically spreading from the stem (e.g. https://www.inaturalist.org/observations/119339461 or https://inaturalist-open-data.s3.amazonaws.com/photos/209907919/original.jpeg). The stipules of tomcat clover are normally not or only a bit spreading and they are not that regularly incised, but have on the upper edge one or a few longer bristle(s) (e.g. https://inaturalist-open-data.s3.amazonaws.com/photos/227735944/original.jpeg or https://inaturalist-open-data.s3.amazonaws.com/photos/209937254/large.jpg or https://inaturalist-open-data.s3.amazonaws.com/photos/205643647/original.jpeg).