Monographs Details: Cassia macedoi H.S.Irwin & Barneby
Authors:Howard S. Irwin, Rupert C. Barneby
Authority: Irwin, Howard S. & Barneby, Rupert C. 1978. Monographic studies in Cassia (Leguminosae, Caesalpinioideae). III. Sections Absus and Grimaldia. Mem. New York Bot. Gard. 30: 1-300.
Description:Latin Diagnosis - Cassia macedoi Irwin & Barneby, sp. nov., foliolis multijugis transversim verticalibus paniculaque terminali nuda exserta C. felicianae similis et vix dubie proxime affinis sed foliolis magis numerosis (usque 20 nec 12-jugis) facie utraque glabris, inflorescentia omnibus partibus aureo-setosa necnon floribus maximis (petalo majori ±24 nec 14 mm longo) eximie distincta.
Species Description - Stout erect shrubs of unknown stature, the stems, lf-stalks and margin of the many crowded, resupinately tilted, elaborately reticulate, concolorous lfts scabrid with livid-based glandular setules up to 0.2-0.5 mm, sometimes also thinly minutely pilosulous, the inflorescence a terminal leafless, densely yellow-setose panicle of stout, simple or weakly branched racemes elevated far above the foliage.
Stipules spreading, stiffly setiform, 2.5-4 mm, becoming dry and easily broken but mostly persistent.
Lvs stiffly divaricate and widely ascending, shortly stoutly petioled, (6-)7.5-13 cm; pulvinus dilated at base, not otherwise differentiated, 1-2.5 mm; petiole 3-10 mm, at middle 0.8-1.5 mm diam shallowly open-sulcate ventrally; rachis (4.5-)6-11 cm; lfts (8-) 10-20 pairs, crowded along rachis, subequal or decrescent from middle in either one or in both directions, variously oriented, the proximal ± reflexed toward the stem and the distal away from it, the median divaricate at right angles, all tilted, proximal margin to the meridian, on stout, when dry wrinkled pulvinule 0.7-1 mm, from ventral view appearing sessile, in outline very broadly ovate to ovate-elliptic, obtuse and mucronulate, or at apex depressedly deltate-acute, (10-)13-25 x 7-20 mm, at base inaequilaterally cordate both sides, the plane, densely setose-ciliolate margin entire or obscurely crenulate, the blades on both faces dull olivaceous, glabrous or sometimes very sparsely and finely pilosulous above, the midrib with 6-9 pairs of major secondary and many tertiary venules all prominulous both sides but more sharply so beneath, forming a mesh of areoles at least in great part <1 mm diam.
Inflorescence a terminal erect leafless panicle of stout simple racemes arising close together from a common axis 0.5-2 cm, densely hispid throughout with golden-yellow glandular setae up to 1.3-2 mm, the axis of individual racemes becoming ±7-15 cm, or some lateral ones shorter, the 1-2 expanded fls raised to level of succeeding buds; bracts spreading, submembranous lanceolate 2-3 mm, persistent; pedicels of fertile flowers 2-3 cm, of sterile ones often shorter, at anthesis ascending, in fruit divaricate, bracteolate 1-6 mm below calyx; bracteoles subulate ± 1 mm, probably persistent; buds ovoid-apiculate, densely setose, glutinous; sepals submembranous, brownish or greenish, elliptic or elliptic-obovate, the outer ones acute, 13-14.5 x 3.5-5 mm; petals yellow, rather narrowly ascending, four plane, unequal, one largest adaxial, all f label late from a short cuneate claw, the largest ± 24 x 21, the smallest ± 19-15 mm, the fifth petal falcately semi- obovate, ± 18 mm, folded lengthwise beyond the androecium but not concealing it; ovary and forming pod densely yellow setose; ovules ±6.
Pod not seen.
Distribution and Ecology - Noted by the collector as arbusto campestre, to be sought in cerrado near 1000 m, known only from the type-locality in the valley of upper Rio Tocantins at 14° 30' S, 48° 30' W, in centr. Goias. - Fl. VII-IX.
A strikingly distinct and handsome cassia, combining the multijugate reticulate foliage of C. feliciana with the large, incipiently zygomorphic flowers of C. orbiculata, and notable further for the long golden setose vesture of the panicle. The identical form of the collectors's name and place of collection is a real coincidence, not (as might be thought) an accidental repetition.
Goiás Brazil South America
| Brazil South America