Cassia lavradiiflora

  • Title

    Cassia lavradiiflora

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Cassia lavradiiflora Harms

  • Description

    116.  Cassia lavradiiflora Harms in Feddes Repert. 20: 124. 1924. — "Brasilien: Goyaz, Fazenda do Lamarao, Campo, (Glaziou n. 20968. .)" — Holotypus †B = F Neg. 1699; clastotypus (fragm.) F! neoholotypus, former isotypus,collected 4.VI.95 (fl), P! = NY Neg. 6927; isotypi, C = NY Neg. 6740, K = IPA Neg. 1151 = NY Neg. 1550, LE, S! — C. lavradiiflora Harms ex Glaziou, 1906, p. 163, nom. nud.

    Slender undershrubs with weak prostrate or ascending simple or distally few-branched, smooth or obscurely gland-verruculose stems radiating from a xylopodium, including the terminal incurved-ascending, far-exserted, loosely racemose or weakly paniculate inflorescence 3-8 dm, below the inflorescence either glabrous (but perhaps subglutinous when fresh) or the margins of leafstalks and blades remotely livid-setulose, the raceme-axis, pedicels and calyx all minutely viscid-villosulous and thinly yellow-setulose, the simplified chartaceous foliage glabrous, subconcolorous.

    Stipules erect, firm, linear-setiform, 3-9.5 mm, dorsally carinate, persistent.

    Lvs unilaterally ascending toward vertical, 3-8(-9) cm, petioled, the lowest and uppermost smallest; pulvinus slightly dilated and discolored, 1-1.5 mm, wrinkled when dry; petiole 9-25 mm, 0.7-1 (-1.2) mm diam, openly shallow-sulcate and narrowly wing-margined; rachis of most (or at least of some lower) lvs 0, of a few (or most) median or distal lvs up to 13 (-20, exceptionally -32) mm; lfts 1, or in a few or most lvs 2 (exceptionally 3 or 4) pairs, when over 1 pair scarcely graduated, tilted forward from rachis and inclined face to face on very short, when dry crosswrinkled pulvinule ± 1 mm, in ventral view appearing subsessile, in outline subsymmetrically ovate-elliptic, broadly obovate, or suborbicular, obtuse or subemarginate to deltately acute, 15-60 x 12-46 mm, at oblique base shallowly cordate both sides, the margin plane entire, the blades stiffly chartaceous, olivaceous or brownish-olivaceous and dull both sides, not or only slightly paler dorsally, the midrib and ± 5-10 pairs of major secondary veins above slightly raised, beneath sharply prominent, the tertiary and subsequent venules faintly prominulous beneath, forming a loose irregular reticulum of plane areoles mostly 1 mm diam.

    Inflorescence terminal, simply racemose or paniculately few-branched, the lower lateral racemes sometimes leafy-bracteate, the axis of the central (or only) raceme loosely few-fld and including the short peduncle (0.5-)1-2 dm, those of lateral racemes or of racemes terminal to lateral branchlets often shorter, the 1-2 fls simultaneously expanded displayed near or close below the racemose buds; bracts firm, triangular- or lance-subulate, 1.3-3 mm, persistent; pedicels ascending, at anthesis slender and somewhat flexuous, in fruit ascending, divaricate, or deflexed 1.5-5.5 cm, bracteolate 5-25 mm below calyx; bracteoles resembling bracts, but only 1 — 1.5 mm, persistent; buds plumply ovoid, apiculate by incurved tip of the outermost sepal, thinly villosulous and yellow- setulose; sepals reddish 8.5-11 x 2.6-4 mm, the outer firm, lance-elliptic, acute, the inner broader, blunter and petaloid-margined; petals (of Absus, little known) yellow, the four plane ones apparently widely ascending, up to 13-16 x ±7-11 mm, the fifth coiled; ovary yellow-setose; ovules 5-8.

    Pod linear-oblong, slightly curved downward, (3-)3.5-5 x 0.6-0.75 mm, the glutinous reddish- brown valves thinly villosulous and hispid or hispidulous with yellow setae up to 0.7-1.5 mm; seeds unknown. — Collections: 9 (some doubtful, see below).

    Campos, the habitat not further elaborated, but to be expected in thin sandy or stony soils of campo limpo, 700-1000 m, known with certaintly only from the sources of Rio S.

    Bartolomeu in Distrito Federal and Sa. Geral do Parana in e.-centr. Goias, but extending probably n. into centr. Chapada dos Veadeiros at ± 14 S, the evidence for the n. extension as yet only sterile. — Fl. II-VII.

    A diffuse or prostrate cassia, almost fully herbaceous above the xylopodium, from which the stems arise anew each year, going out without interruption of the ontogeny into a terminal inflorescence. The habit is that of C. cristalinae, C. neesiana var. laxiracemosa, or C. decumbens, except that the leaves are simplified down to one or two, exceptionally three or four pairs of relatively large, broadly ovate to orbicular leaflets, little differentiated dorsoventrally either in color or reticulate venulation. A notable feature of C. lavradiiflora is the pair of herbaceous wings running the length of the petiole's adaxial face enclosing an open gutterlike groove, The petiole resembles that of C. planifolia, although longer in proportion to size of the leaflets, and that of C. roncadorensis, which has revolute leaflets. Of these two only the latter is similar in its diffuse stems, while very different in the constantly bijugate, at once larger and proportionately narrower leaflets. In general aspect the unifoliolate form of C. lavradiiflora is reminiscent of C. cotinifolia, although different in leaf-outline and especially in the relatively long stipules, a feature that occurs in no other species of ser. Ochnaceae. The true affinities of the species remain controversial, and it is inserted here in our account for want of an obviously more appropriate place.

    A clear photograph of the lost Berlin specimen of C. lavradiiflora confirms Harms' description of the leaves as all bifoliolate. This is true also of the duplicate material now at C, K, P, and L, but the isotype at S includes two stems bearing near the middle a few 4-foliolate leaves, the pairs separated by a rachis about 1 cm long. Out of four collections now known from Distrito Federal, two (Glaziou s.n. from Santa Luzia; Irwin & Soderstrom 5934 from Parque do Gama) have uniformly bifoliolate leaves and except for slightly ampler leaf-blades remotely setose-ciliolate are excellent matches for the type; the third (Irwin & Soderstrom 6023 from the Anapolis road) has in some plants one or several 4-foliolate leaves above middle of each stem; in the fourth (Heringer & Sucre 599 from Chapada do Rio Preto) bijugate leaves predominate. A fragmentary specimen collected by Blanchet (s.n., BM), perhaps in interior Bahia but the locality not recorded, differs from other material of C. lavradiiflora in its short stipules (± 1.5 mm) and absence of setules in the inflorescence; it may represent a taxonomically distinct variety.

    As noted above, C. lavradiiflora is believed to extend north from the Distrito along the Tocantins-Parana divide as far as Alto Paraiso near 14° S. Unfortunately the three collections from Chapada dos Veadeiros are sterile. The specimens resemble C. lavradiiflora closely except for the presence of occasional leaves with 3 or even four pairs of leaflets. Flowering material is essential for firm identification of these plants.