Monographs Details: Chamaecrista nictitans subsp. patellaria var. paraguariensis
Authors:Howard S. Irwin, Rupert C. Barneby
Authority: Irwin, Howard S. & Barneby, Rupert C. 1982. The American Cassiinae. A synoptical revision of Leguminosae tribe Cassieae subtrib Cassiinae in the New World. Mem. New York Bot. Gard. 35, part 2: 455-918.
Family:Caesalpiniaceae
Synonyms:Cassia flavicoma var. paraguariensis Chodat & Hassl., Cassia gemina Vell., Cassia hypnotica Vell., Cassia chamaecrista var. hypnotica (Vell.) N.F.Mattos, Chamaecrista simplex Standl., Cassia simplex (Standl.) Standl., Chamaecrista browniana Britton & Rose, Cassia pennelliana Amshoff, Cassia browniana Kunth
Description:Species Description - Erect, obligately monocarpic herbs at anthesis (2.5-)3.5-15("-25") dm, commonly simple wandlike, sometimes (when robust) strictly few-branched distally, branched at base only when cut or injured, the stems and lf-stalks strigulose with subappressed, incumbent, or straighter, narrowly ascending hairs up to 0.25-0.7(-0.8) mm, nowhere setose, the concolorous foliage except for minutely scabrid-ciliolate lfts glabrous, only the pod loosely pilosulous, exceptionally glabrous throughout. Stipules erect, lance-acuminate, those associated with larger adult lvs and flowers (6.5-)7.5-21 mm, at subsymmetric base (1.2-) 1.5-3 mm wide, from base strongly 10-17-nerved, the blades glabrous dorsally, minutely ciliolate. Lvs ascending and often incurved, heteromorphic, the early ones relatively short and simple, those (alone described hereafter) at middle and fertile nodes up to (5.5-)7-15(-21) cm, short-petioled, the expanded blade in outline narrowly lance-elliptic to linear-oblong; petiole including pulvinus (4-)4.5-9.5(-14) mm, above the gland narrowly coarsely margined, openly sulcate and 0.5-1.2 mm diam; glands 1-2, situated near middle of petiole proper, scutellate or patelliform sessile, in outline nearly always elliptic longer than wide, but when small subcircular, the one or the larger of a pair up to (0.7-)0.9-3.2(-4) mm diam, in profile always much wider than tall; lfts up to (19-)20-38(-44) pairs well spaced along rachis, in outline narrowly oblong, narrowly oblong-elliptic, or ovate-elliptic, obtuse mucronate or subacuminulate, the largest of larger lvs of a given plant up to (5.5-)6.5-20(-22) x 1.3-4.6 mm, at base angulately cordate on the broad and cuneate to rounded on the narrow side, from base 6-9-nerved by the costa with on the broad side 4-6, on the narrow one 1-2 primary nerves, the costa thence penniveined, with 4-9 major pairs of secondaries and commonly but not always as many intercalary ones, the latter varying from faint or subobsolete (externally) to almost as strong as the major set, the venulation therefore appearing either laxly or closely parallel-lineolate, usually prominulous on both faces but often more sharply so and pallid beneath. Peduncles at most nodes paired, the inner (4-)6-24 mm, adnate its whole length, mostly 2-4, rarely 5(-6)-fld, the exterior one very short or obsolete, becoming axillary, in some slender individuals represented by mere rudiments of bracts; pedicels at anthesis 2.5-6(-9) mm, in fruit ascending, thickened 3.5—8(—11) mm, bracteolate 1-2.5 mm below calyx; bracteoles ovate- or lance-acuminate (1.5—)2—5 mm; buds slenderly ovoid-acuminate, especially along midrib of outer sepals thinly strigulose-pilosulous, rarely glabrous; sepals ovate- and lance-acuminate up to (4.5—)6—14.5 mm; petals yellow, seldom widely expanding, all very variable in length and amplitude, the 3 adaxial oblanceolate to broadly obovate-cuneate 5.5-15 x 4.5-8 mm, the long abaxial one either similar to the last or longer, broadly oblanceolate to flabellate (5.5—)6.5—14(—16) mm, the cucullus obliquely obovate or transversely dilated-reniform, usually a little shorter than the last, 5.5—13(—14) x 5-10 mm; long anthers (4.4—)5.5—9.5 mm; ovary densely strigulose- pilosulous, exceptionally glabrous; style linear or when short slightly dilated distally, never very strongly incurved, 0.8-4(-5.5) x 0.3-0.55 mm; ovules (9-) 11-22. Pod erect, straight or slightly curved outward, (27-)30-60(-66) x 3.5-5.2 mm, the castaneous or purplish-red, finally nigrescent valves densely pilosulous with fine ascending hairs; seeds 2.7-3.3 mm, the fully ripe testa sublustrous, fuscous black-pitted or soot-black overall, the pits shallow, sometimes faint.—Collections: 95.—Fig. 36 (petiolar nectary).

Distribution and Ecology - Seasonally wet grasslands (savanna, campo, llano), thickets in scrubland, disturbed woods, cerrado, sometimes becoming weedy in hedges, roadsides, fallow news and orchards, in Central America ascending into the pine-oak belt, mostly between 450 and 1000m, but in Panama and on the llanos of e. Colombia at 20-450 m, in the inter-Andine valleys of Colombia to 1500-1700 m, and in s.-e. Brazil to 1200 m, discontinuously widespread both n. and s. of the Amazonian Hylaea. s. Mexico (Tabasco, Guerrero, Oaxaca, Chiapas) to Colombia (s. in Cauca valley to Cauca, in Magdalena valley to Tolima, e. to Int. Meta) and rarely to Venezuela (Cord. Costanera in Aragua and D.F.; Gran Sabana in Bolívar); disjunctly on the Brazilian Planalto from s. Ceará s., between Rios São Francisco and Xingú, to w. Minas Gerais, centr. and w. São Paulo, and w. Paraná, thence e. rarely into Rio de Janeiro and commonly w. through s. Mato Grosso to e.- centr. Paraguay and the Yungas in trans-Andine Bolivia.—Fl. n. of the Equator mostly VI-II(-IV), to the s. mostly XI-V.

Discussion:

We assemble here under the name of Ch. nictitans var. paraguariensis all those obligately monocarpic Chamaecristae Mimosoideae characterized by simple wandlike stems, sessile patelliform petiolar glands, narrowly elongate multifoliolate adult leaves and short-pedicelled flowers, which have passed in Central America and Colombia as either C. simplex or Ch. browniana (=C. pennelliana) and in Brazil either as C. subtriflora (which really = Ch. repens multijuga) or some variety of C. chamaecrista or C. flavicoma. There is little new in our consolidation of names, for Woodson & Schery (1951, p. 62) have already recognized the taxonomic synonymy of C. simplex, described from lowland Panama, and C. pennelliana, described from middle elevations in Colombia and El Salvador; while Britton long ago (in annotation, NY) admitted the latter to the flora of Bolivia in the shape of Bang 549 and Rusby 2854, plants certainly conspecific with the typus of Paraguayan C. flavicoma var. paraguariensis. Thus the chain of synonymies, established in advance, only requires positive assertion. For want of type specimens some residual doubt clings to the identity of C. gemina and C. hypnotica Veil., one of which we believe to be the oldest of all applicable names at the specific level, the more so because the plant has been found only once (W. Hoehne 6007, NY) in modern times on the Atlantic slope of southern Brazil and was probably therefore not native "in excultis maritimis" within the range of Flora Fluminensis. But since, like so many other chamaecristas, var. paraguariensis is often at least potentially weedy, considerations of range do not weigh heavily here. Vellozo’s plate of C. hypnotica agrees in all details with large-flowered Brazilian forms of var. paraguariensis, showing the annual root, the simple stem, the sessile glands, the many (to 22 pairs) small ovate-oblong leaflets with subcentric, penniveined costa, and the short pedicels that together characterize no other chamaecrista known to us, certainly none of the three taxa (Ch. nictitans subsp. patellaria var. ramosa, subsp. disadena var. pilosa and Ch. glandulosa var. brasiliensis) encountered today in coastal Rio de Janeiro or Guanabara. Bentham’s reduction of C. hypnotica to his own C. chamaecrista var. brasiliensis (—Ch. glandulosa brasiliensis), a shrub with no more than 12 pairs of leaflets in the largest leaves, is difficult to comprehend.

Multiple similarities in habit and morphological detail point to a very close relationship between var. paraguariensis, var. glabrata and subsp. brachypoda. The latter identical in habit, differs essentially only in the dorsally pubescent stipules and the absolutely fewer (at most 14, not 20-40) pairs of leaflets, which tend to be larger though identical in venulation. On the other hand it is the more excentric midrib and simpler secondary venulation of the leaflets that alone ultimately distinguishes var. glabrata. The petiolar glands of each of these three related cassias are quite variable in size and offer no firm differential characters. The coarse multifoliolate (sometimes polyploid) race of var. glabrata found in the Amazon delta region and described by Bentham as C. patellaria var. longifolia resembles some individual small-flowered var. paraguariensis in everything but the leaflet venation. The middle Amazonian glabrate form of Ch. nictitans disadena is another habital doppelganger for var. paraguariensis but nevertheless recognized at once by the venulation and the coarsely turbinate, not shield- or dish-shaped petiolar glands.

The perianth of var. paraguariensis is extremely unstable in size, the petals together with long anthers and styles varying together in what appears to be a continuous series only imperfectly correlated with geographical dispersal and, furthermore, subject to seasonal modification on a given plant. The largest and smallest flowers are not sympatric, however. The former, with styles 2-4(-5.5) mm long, occur only on the Brazilian Planalto, within the range of the related subsp. brachypoda, from which it seems possible that genes for large, outcrossing flowers may have been derived. The smallest, probably autogamous flowers, with styles only 0.8-1.7 mm long, often associated with the slender habit of growth and small leaflets which are the sole peculiarities of the ecotype known as Cassia simplex, are found only northward from Guayana and Colombia. But flowers of moderate size have been encountered at both extremities of the variety’s range, in Mexico and in southern Brazil and Paraguay. A noteworthy character of var. paraguariensis, very unusual in Ch. nictitans sens. lat., is the relative uniformity in vesture, the setose type of trichome being quite suppressed. A minor variant (Anderson 11330, CURI, NY), completely hairless even to the ovary, superficially resembles the glabrate Cuban form of var. glabrata segregated by Britton as Ch. glaberrima.

Distribution:Panama Central America| Colombia South America| Brazil South America| Mexico North America| Tabasco Mexico North America| Guerrero Mexico North America| Oaxaca Mexico North America| Chiapas Mexico North America| Cauca Colombia South America| Magdalena Colombia South America| Tolima Colombia South America| Meta Colombia South America| Venezuela South America| Aragua Venezuela South America| Bolívar Venezuela South America| Distrito Federal Venezuela South America| Ceará Brazil South America| Minas Gerais Brazil South America| São Paulo Brazil South America| Mato Grosso Brazil South America| Paraguay South America| Yungas Bolivia South America| Bolivia South America|