Cassia × regia Standley, stat. nov. (=C. grandis x moschata). C. regia Standley, Contrib. U.S. Nat. Herb. 18: 103. 1916.—"Type [US] no. 677196, collected around El Paraiso, Canal Zone, Panama, altitude 30 to 100 meters, January 24, 1911, by H. Pittier (no. 2532)."—Holotypus, US! isotypus, US! clastotypus, NY!
Cassia regia sensu Britton & Rose, 1930, p. 230; Schery, 1951, p. 47, in nota sub C. grandi.
The hybrid origin of C. regia as the offspring of C. grandis x C. moschata was plausibly suggested by Schery (1951, l.c.). The type-collection has the pliantly pendulous raceme, the long hypanthium, the red sepals and the unmodified vexillum of C. moschata but the open corolla and small pilosulous obtuse anthers of C. grandis. Standley described the petals, from dried specimens then five years old, as pale yellow with conspicuous purple veins, but fresh color is indecipherable from dried specimens in this group, pink and yellow petals often turning nearly the same shade of buff-orange when dried. A similar plant with petals noted in the field as salmon-pink was collected by Britton (no. 12889) in a pasture at Cristo near Santiago in eastern Cuba, close to normal C. grandis (no. 12901). The two supposed parents are native in similar habitats in Panama and C. moschata was cultivated in the vicinity of Santiago not far from Cristo (El Caney, Britton 1856, NY), so the possibility of contact is established. Controlled hybridization should be attempted to settle the question.