Cassia myrophenges H.S.Irwin & Barneby
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Authors
Howard S. Irwin, Rupert C. Barneby
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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.
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Family
Caesalpiniaceae
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Scientific Name
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Type
Holotypus, NY; isotypi, RB, US.
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Synonyms
Cassia vernicifolia Taub.
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Description
Latin Diagnosis - Cassia myrophenges Irwin & Barneby, sp. nov., glabritie, viscositate aliisque notulis C. hedysaroideae formas microphyllas sympatricas simulans, sed petiolo alato-marginato, foliolisque (siccis) utrinque alte reticulatis ac glutinoso-lucidis (nec superne opacis subeveniis), a forsan propius affini C. lentiscifolia petioli communis structura comparanda f ol io I is elliptico-oblanceolatis 7-14 (nec -linearibus 3-6) mm latis, racemis paucifloris, necnon sepalis subduplo majoribus (17-18 nec 9-9.5 mm longis) longe acuminatis petala subaequantibus certe diversa.
Species Description - Shrubs of rounded outline to 3 m, glutinously lustrous throughout and appearing glabrous up to the glandular-setulose and -villosulous inflorescence but the pulvinules, margins of leafstalks and lfts microscopically puberulent, the brownish stems verruculose, paniculately branching distally, the foliage concolorous, the lfts subequally reticulate both sides, conspicuously resin-dotted beneath, the short, few-fld racemes not or scarcely exserted. Stipules appressed, triangular-subulate, 0.4-1.2 mm, apparently deciduous but often held fast and concealed by glutinous exudate. Lvs ascending (3-)4-14 cm, petioled; pulvinus ovoid, dilated, subglandular, 1-4 mm, wrinkled when dry; petiole (0.9-) 1.3-3 cm, 0.8-1.2 mm diam, openly grooved and narrowly wing-margined ventrally; rachis of most lvs 1.5-6 (of some small distal lvs 0-1.5) cm, the ventral wings of each segment widened upward; lfts of most lvs 3 or 4 (of some small lvs associated with inflorescence only 1-3) pairs, spreading-ascending from rachis, face upward, on dilated glandular-puberulent pulvinule 1-1.6 mm, slightly decrescent upward, in outline elliptic-oblanceolate, (1-)1.6-4.5 x 0.7-1.4 cm, obtuse or emarginate but mucronulate by the excurrent midrib, the plane, entire or minutely undulate, cartilaginous margin microspically puberulent, the blades firmly chartaceous, olivaceous and lustrously glutinous on both sides, densely resin-dotted beneath, the midrib,the ±4-6 pairs of major secondary veins, as well as the connecting tertiary and reticular venules all subequally prominulous on both sides, only the midrib slightly more pronounced beneath, forming a discolored (brownish) keel. Inflorescence terminal to distal branchlets clad in relatively small and simpler lvs, simply racemose or incipiently racemose-paniculate, the lateral axes when present very short and commonly leafy-bracteate, the axis ±4-10-fld, 1-3 cm, sometimes produced as a leafy shoot beyond the last fl; bracts deltate or oblanceolate, 1-2.7 mm, subpersistent; pedicels ascending, ± 12-17 mm, bracteolate 1-6 mm below calyx; bracteoles like bracts, slightly smaller; buds plumply ovoid, sharply acuminate, thinly setulose; sepals submembranous greenish, ovate-elliptic acute or acuminate, 17-18 x 3.8-6 mm; petals (of Absus, scarcely known) yellow, apparently hardly longer than the sepals; ovary densely setulose; ovules 4-5. Pod oblong, 20-33 x 7-8 mm, the purplish-castaneous, glutinously lustrous valves remotely bulbous-setulose, otherwise glabrous; seeds unknown. — Collections: 4. Plate 18.
Distribution and Ecology - Sandstone outcrops, 1050-1300 m, local, e. slope of centr. Sa. do Espinhaço between 18° 5' and 18° 35' S (Birybiry; Diamantina to Mendanha; Serro) in centr. Minas Gerais. — Fl. VIII-IX.
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Discussion
The first known collection of C. myrophenges was sterile and reported by Glaziou (1906, 1.c.) as C. vernicifolia Harms (nom. nud.), in association with a fertile specimen of C. hedysaroides, the glabrous and glutinous cassia common and frequently collected around Diamantina. It resembles the smaller-leaved forms of C. hedysaroides in habit of growth, number of leaflets, shortly few-flowered racemes, and short, few-seeded pods, but is readily distinguished by the distinctly wing-margined leaf-stalks and especially by the concolorous leaflets, equally glossy on both sides and not drying dull above. The leaflets of C. hedysaroides are pinnately veined but pronounced tertiary or reticular venules are invisible externally; in C. myrophenges the reticulation is equally and sharply prominulous on both faces of the leaflets, the ultimate mesh formed by venules of the fourth order of ramification. A possibly closer relative is the still poorly known C. lentiscifolia, similar in the openly grooved, green-winged leaf-stalk, but clearly different in the combination of linear-oblanceolate leaflets and many-flowered racemes of smaller flowers with petals well-exserted beyond the much smaller sepals. The epithet, meaning "shining with unguent", refers to the glossily glutinous foliage. See also discussion of the closely related C. semaphora.
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Distribution
Minas Gerais Brazil South America| Brazil South America|