Cassia cristalinae

  • Title

    Cassia cristalinae

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Cassia cristalinae H.S.Irwin & Barneby

  • Description

    60.  Cassia cristalinae Irwin & Barneby, sp. nov., C. neesiana var. laxiracemosae habitu humifuso praesimili affinis sed ab eo foliis subsessilibus, foliolis brevioribus (saepissime 5-11-, rarius 1 4-jug is) sepalisque brevioribus (7-8.5 mm tantum longis) vix dimidium petalum longiorem superantibus distans— BRAZIL. Goias: cerrado, Cristalina, 7. VI 1.1963 (fl), A. Mattos 358 e Heringer. - Holotypus, RB = NY Neg. 8822. - Plate 7.

    Prostrate humifuse undershrubs with simple or sparingly branched stems arising yearly from a knotty xylopodium, the stems and foliage thinly or densely hirsutulous with spreading- incurved hairs or the concolorous lfts glabrous ciliolate, the terminal far-exserted, simply racemose or incipiently paniculate inflorescence densely glandular-setulose.

    Stipules narrowly subulate 1.5-2 mm, becoming dry but persistent.

    Lvs obliquely ascending toward meridian, 2.5-6 cm, subsessile or very shortly petiolate, the lf-stalks hirsutulous (especially ventrally, where sulcate) with spreading hairs; petiole 1-3 mm, narrowly sulcate; rachis (2-)2.5-5 cm; lfts 5-11 (-14) pairs, spreading or ascending from rachis, turned half face to face on pulvinule up to 0.1-0.5 mm, slightly diminished upward, in outline broadly oblong-ovate or -elliptic muticous or minutely mucronulate, (3-)4-12 x 2.5-4.5 mm, at base strongly asymmetric, cordate on proximal and rounded on distal side, the entire plane margins pectinately ciliolate with forwardly curved hairs, otherwise either glabrous except for random hairs on costa beneath or pilosulous on both faces, the blades firmly chartaceous, on both sides brownish-olivaceous, densely papillate, dull or (young) a little lustrous, the costa and 3-4 pairs of secondaries faintly visible above, prominulous beneath.

    Racemes terminal to main stems and axillary to a few reduced uppermost lvs, incurved toward vertical, laxly many-fld, the axis including short peduncle to ± 12 cm; bracts submembranous, narrowly ovate 1.2-1.5 mm, persistent; buds subglobose, minutely apiculate; sepals submembranous, red-tinged, ± 7-8.5 x 3.5-5 mm; petals yellow, ± 12-15 mm, 4 cuneate -flabellate up to 7-10.5 mm wide, the odd one oblong-oblanceolate, coiled; ovary densely hirtellous and glandular.

    Pod glandular-setose, not seen ripe. — Collections: 5.

    Open grassy places in cerrado, 900-1050 m, apparently very local, known only from Sa. dos Cristais near Cristalina and Sa. do Facao near Catalao in s.-e. Goias. — Fl. VI-VIII.

    With its pliantly humifuse stems that give rise to one or few terminal lax racemes incurved to vertical, C. cristalinae closely mimics the probably closely related C. neesiana var. laxiracemosa, but differs in the subsessile leaves (petiole 1-3, not 5-20 mm) with fewer (5-11, rarely 14, not 10-18) pairs of leaflets. The flowers of these two cassias are similar in size but differently proportioned, the petals of C. cristalinae being almost twice, not one fourth to one third longer than the sepals. The also habitally similar C. venatoria, remotely allopatric northward on Chapada dos Veadeiros, has larger, mucronate, reticulate leaflets and longer stipules (3-5.5 not 1-2 mm); while C. benthamiana, a third humifuse cassia of the Goias highlands, also with subsessile leaves, has leaflets divaricate from rachis and turned edgewise to the meridian in the attitude proper to ser. Rigidulae.