Taxonomie : D'après R.C. Barneby & J.W. Grimes (Mem. New York Bot. Gard., 74(1):
39-
40.
1996 [25/03/1996, fide
p. de titre]): "We have no solution to the mystery surrounding
Mimosa chrysantha Vahl (Eclog. Amer. 2:
38. 1798), which Bentham* (1875:
588) attributed with reservations to
Pithecolobium pedicellare. The holotypus, collected at Cayenne by von Rohr, was seen by Bentham in Vahl's herbarium, but can no longer be located there (Mrs. Fox Maule,
in litt.!). The leaf-formula given in the protologue is compatible with
B. pedicellaris, but the abscence of petiolar nectary and yellow color of the corolla are not. De Candolle (Prodr. 2:
471), who knew it only from description, hesitantly referred
M. chrysantha to
Acacia. The only bipinnate species of Ingeae with yellow flowers likely to have been found in French Guiana is
Zygia (
Marmaroxylon)
racemosa, but this has nectaries that could hardly have been overlooked."
Pourtant la solution de ce mystère avait en réalité déjà été résolue par ces mêmes auteurs six ans plus tôt! Ils avaient en effet parfaitement détecté l'holotype de
Mimosa chrysantha Vahl dès 1989 à New York (comme l'atteste leur determinavit), avaient alors sans hésitation conclu qu'il s'agissait d'
Acacia glauca (L.) Moench 1794 [≡
Acaciella glauca (L.) L.Rico 2006] et avaient par la même occasion, et logiquement, émis des doutes sur l'origine du type (voir notes in sched.
C10011406 &
C10011407). En fait il est probable que si ce type n'avait pas été relocalisé à Copenhague, c'est tout simplement qu'il était alors en prêt à New York... Notons enfin, qu'un isotype (BM) a été déterminé comme
Acaciella glauca par Rico Arce & Bachman (
2006) et que ces auteurs indiquent "Martinique" comme provenance!
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* "
Mimosa chrysantha, Vahl, Ecl. ii.
38 (
Acacia chrysantha, DC. Prod. ii.
471), from Cayenne,
v. Rohr, is probably this species [
Pithecolobium pedicellare Benth. =
Hydrochorea pedicellaris] or one closely allied to it. When I saw the specimen in Vahl's herbarium, it appeared to me to be the Jamaican
P. filicifolium; but that is not a Cayenne plant, and agrees less with Vahl's description than the nearly allied Cayenne
P. pedicellare. The only objection is Vahl's express statement "Petiolus eglandulosus," whereas in
P. pedicellare
there is usually a prominent gland about halfway from the base to the
lowest pair of pinnae. De Candolle has reversed the numbers respectively
assigned by Vahl to the pinnae and the leaflets; but that is owing to
Vahl's having, in common with many of the older botanists, always given
the name of
foliola to the primary divisions of the leaf now called
pinnae, and that of
pennulae to the secondary segments now always termed
foliola or
leaflets." [Bentham, Trans. Linn. Soc.London, 30(3):
588. 1875].
Type : "Habitat in Cajenna. von Rohr. ♄" [protologue].
Origine inconnue ["Cayenne" sans doute par erreur, ou alors cultivé; mais plus probablement Antilles néerlandaises ou côte caraïbe du Venezuela], s.d., J.P.B. von Rohr [ou J. Ryan?] 134 (HT*:
C10011406 [ex hb. Schum.; "
Mimosa chrysantha Vahl" "
Mimosa alba Rohr" "Ryan" "Rohr" "134"],
C10011407 [ex hb. Vahl; "
Mimosa tetrastachys chrysantha" "
alba Dn. v. Rohr no 134"]; ILT: BM ["Martinique: van Rohr 134" fide Rico Arce & Bachman, Anales Jard. Bot. Madrid, 63(2):
212. 2006 sub
Acaciella glauca (L.) L.Rico 2006; non trouvé en ligne G.Léotard 12/05/2023!]).
* une première étiquette indique: "Holotype of
Mimosa chrysantha Vahl Ecl. amer. 3:
38. 1807. v. Rohr 134" (det. R.C. Barneby & J.W. Grimes, 1989).
Et une seconde étiquette précise: "These specimens closely agree with the protologue of
Mimosa chrysantha Vahl (Ecl. 3: 38.1807) and are confidently identified as the HOLOTYPE. The two sheets seem to be of one collection, although both Ryan's name as well as that of von Rohr appear on back of sheets. Bentham (Trans. Linn. Soc.London, 30:
588. 1875) mis-associated
M. chrysantha with
Pithecellobium pedicellare, although he noticed the lack of petiolar nectary in the protologue, which would be incompatible with the
Pithecellobium. The plant is said to come from Cayenne, but the species has not been collected since in the Guianas. It is the
Acaciella curassavica B. and R., for which the oldest name, in genus
Acacia, is [Howard, Fl. Lesser Antilles 4: 339. 1988]
A. glauca (L.) Moench." (R.C. Barneby & J.W. Grimes (NY), 1989).
