Senna silvestris (Vell.) H.S.Irwin & Barneby var. silvestris

Family

Caesalpiniaceae

Scientific Name

Senna silvestris (Vell.) H.S.Irwin & Barneby var. silvestris

Type

Holotypus, the cited plate!

Synonyms

Cassia lucens Vogel, Cassia silvestris Vell., Cassia racemosa var. tenuifolia Huber

Description

Variety Description - Arborescent on riverbanks and in forest, then 5-20(-30) m tall, sometimes arborescent and distally sarmentose, in capoeira, cerrado and savanna flowering precociously as coarse suffrutices or soft-woody shrubs (2-)3-6 m, the lfts glabrous above, pubescent either overall or only along principal veins with straight sppressed or ascending hairs up to (0.15-)0.2-0.6 mm, the reticulartion of upper face of lfts either sharply prominulous or immersed, that of lower face prominulous, but the areoles plane and shallow; lvs mostly (2.5-)3-6 dm, shorter only at or near base of panicle; lfts (6-)7-11(-13) pairs, the larger ovate- or lance-acuminate from rounded base, (6.5-)7-13(-15.5) X 2-4(-4.3) cm; flowers variable in size, the longer inner sepals mostly 7.5-11(-13), in Peruvian and adjacent Brazilian Amazonia only 6.5-7.5 mm, the pure yellow petals (9-)13-21(-23) mm; long anthers (5-)6-9(-11) mm; ovary either glabrous, or ciliolate along sutures or pilosulous overall; ovules 36-60; body of pod (12-)15-24(-27) X 1.6-2.8(-3.3) cm, the locules 1-seriate or, in very wide pods, a few of them laterally displaced and randomly 2-seriate.--Collections: 192.--Fig. 10 (androecium), 13 (pod + seed), both under synonym lucens.

Distribution and Ecology - Forest margins, especially along riverbanks and shores and in gallery-savanna ecotone, both in varzea and terra firme, in disturbed woodlands, and savanna thickets, becoming a vigorous pioneer in capoeira, mostly between 15 and 500 m but ascending to 1200 m on Guayana Highland (Sa. Tepequem), to 750 m along inter-Andean valleys in Peru, to 900 m in the Bolivian Yungas, and to 1500 m in s. Sa. do Espinhaco in Minas Gerais, bicentric in dispersal; widespread and locally common over the Guayana Highland and whole Amazonian Hylaea from middle Orinoco valley s. to lat. 17°S in Bolivia and 14°S in Mato Grosso, w. in Peru to the middle Maranon, upper Huallaga and Middle Ucayali valleys, e. to the interior of the Guianas and in Brazil to the middle Tocantins valley and n. Maranhao, n. in Venezuela to Maracaibo Basin; disjunct on the Atlantic slope and coastal forest of s.-e. Brazil: s. Bahia (very local near Vitoria da Conquista), highland s.-e. Minas Gerais (Sa. da Caraca, Caiete and vicinity), and along the foothills of the Coast Range from s.-w. Rio de Janeiro to Santa Cararina. Fl. in the Hylaea year around, most prolifically VIII-IV, in s.-e. Brazil XII-III.

Local Names and Uses - Wood hard, used for gunstocks in Maranhao

Discussion

The most widespread variety of its species, var. silvestris is predominantly a senna of forest margins in the Hylaea, from which it has radiated west into the Andean foothills and south into the cooler wet forest of Atlantic Brazil, becoming a composite of minutely different genetic races. Our attemts to extricate these in the form of useful and meaningful taxanomic units have not succeeded, the variable characters of vesture, flower-size and number of leaflets being poorly correlated and subject to individual as well as racial variation. The most noteworthy examples of the latter are 1) a small-flowered type dominant on the upper forks of the Amazon in Peru and adjacent Brazil, the flower at its smallest (long sepals 6.5-7.5 mm, long petals 9-12.5 mm, with proportionately diminished androecium) resembling that of Cuban S. gundlachii (=var. tenuifolia Huber, cited in the synonymy) and 2) sympatric with normal Hylaean var. silvestris on the upper Madeira and its tributaries in Rondonia and adjoining states a plant different in having relatively few (5-8) and ample pairs of leaflets combined often but inconsistently with a narrow pod (±10-15 mm wide). This narrower pod resembles that of subsp. bifaria var. velutina, also found near the belt of transition between the Planalto and the Amazon forest, but its foliage is that of subsp. silvestris, sometimes approaching with uncomfortable closeness that of var. sapindifolia. An exceptionally wide pod (27-33 mm) occurs at random points in the Amazon Basin and on the Guayana Highland. In it some seeds are commonly displaced from vertical alignment down the middle of the pod, but the seeds are never sorted in two regularly alternating rows as in subsp. bifaria var. bifaria. Contrary to expectations, the populations native to mountainous Minas Gerais and to the coast ranges of south-eastern Brazil, far distant from the variety's main range, seem to have aquired no distinctive qualities. Probably it was in this region that Sello collected from Sa. de Caraca and Caiete.

Identification of Cassia silvestris Vell., in which we differ from all antecendents, depends on interpretation of the protologue, for no specimen survives. Two elements of the protologue are, in our opinion, crucial and decisive: the type locality at the imperial fazenda of Sta. Cruz on the coastal plane to the west of Rio de Janeiro city; and the figure of the pod, so drawn as to show the inner face of the valves with a single row of locules. Bentham, placing greater emphasis than seems justified in our present state of knowledge on shape of the leaflets, which are shown distinctly even though very shallowly cordate at base in Vellozo's plate, identified C. silvestris with what is here called var. bifaria, the common planaltine plant which is not known to cross Sa. da Mantiqueira and differs from the coastal one in its broad, thich textured, coarsly veiny pod enclosing a double row of seeds. From the plate alone C. silvestris might be out var. unifaria, or the C. lucens of Vogel and modern authors. But only the last of these is found today on the Atlantic coastal plain. Bentham's use for C. lucens of the name C. racemosa Mill. has rightly been challenged by Amshoff (1939, l.c.), who examined the typus of latter at the Birtish Museum but was unable to identify it other than negatively. The name C. racemosa is taken up in this revision for the Mexican and Cuban C. ekmaniana Urban.

Common Names

Brujillo, Katawerewere, paricá, Mucurão, yacucaspi, quillu-sisa, tampush, shanshan, mamuri

Distribution

Minas Gerais Brazil South America| Mato Grosso Brazil South America| French Guiana South America| Guyana South America| Suriname South America| Maranhão Brazil South America| Rio de Janeiro Brazil South America| Santa Catarina Brazil South America| Yungas Bolivia South America| Peru South America|