52 R - Knuth. — Oxalidaceae. 



10. 0. nigrescens A. St. Hil. Fl. Bras. Mer. I. (1825) 91, n. 10; Zucc. in Abb. 

 Akad. Muench. I. (1829—30) 247, n. 74; Prog. in Mart. Fl. Bras. XII. 2. (1877) 

 497. — Äcetosella nigrescens (St. Hil.) 0. Kuntze, Rev. Gen. I. (1891) 92. — Radix zb 

 borizontalis, nigra. Caulis suffruticosus, apice subherbaceus, 20 — 30 cm altus, erectus, 

 simplex, basi teres, superius complanatus, angulosus, pilosiusculus, nigrescens vel ob- 

 scure rufescens. Folia sat numerosa; foliola media inferiorum vel mediorum caulinorum 

 ovata vel ovato-oblonga, obtusa, circ. 1 7 mm longa ; superiorum oblonga vel elliptico- 

 oblonga, obtusa, circ. t l fa — 5 cm longa; summorum oblongo-elliptica aut elliptica, 

 saepe lineari-oblonga, obtusiuscula vel linearia, acuta; lateralia minora; omnia integer- 

 rima, glaberrima, subglaucescentia, marginibus saepe nigrescentia vel atropurpurea aut 

 obscure nigra, per validissimam lentem farinaceo-tuberculata ; petiolulus medius circ. 

 4^2 mm longus; petioluli laterales circ. 1 3 / 4 mm longi, villosi; petiolus 1 3 /4 — ^h cm 

 longus, pilosus, supra pubescens. Pedunculi circ. 5 — 6 l / 2 cm longi, complanati, glabri, 

 saepe nigrescentes, apice 2-fidi, infra ramulos 2-bracteati; ramuli 4*/2 — 17 mm longi, 

 divaricati, interiore latere a basi floriferi, florum evolutione gradatim crescentes, ad basin 

 cujusvis floris bracteolati; bracteae subulatae, glabriusculae, nigrescentes. Flores race- 

 mosi, subdistantes, pedicellati; pedicelli circ. 4^2 mm longi, glaberrimi, nigrescentes. 

 Sepala glaberrima, saepe nigrescentia, oblonga, obtusa, mucronulata, 5-nervia. Petala 

 circ. G 1 /} mm longa, aurantiaco-lutea, glaberrima. Stamina minora pistillo breviora; 

 maiora eodem longiora; filamenta minorum eis maiorum 5-plo breviora glaberrima, 

 maiorum hirtella basi glaberrima. Styli crassi, externe hirtelli, ceterum glabri. Ovarium 

 glaberrimum; loculi 3-spermi. Capsula circ. i i / 2 — 6*/j mm longa, ovato-globosa, saepius 

 2-sperma. Semina circ. 3 mm longa. 



Brasilien: Prov. Minas Geraes, Minas novas, auf Feldern (St. Hilaire — Typus). 



Ser. d. Rhombifoliae R. Knuth. 



A. Inflorescentia exacte biramosa; pedunculi 5 — 6 cm longi; 



rami 1 — 3 cm longi. — Rio de Janeiro ; Goyaz 11.0. elatior. 



B. Inflorescentia parum perspicue bilateralis; pedunculi tantum 

 2 cm longi; rami */ 2 — I cm l° n g^ 



a. Caulis i sparsim ramosus, ramis erectis. — Mexiko; 



Guatemala; Costarica; Colombia; Venezuela 12. O . rhombi folia. 



b. Caulis superne squarroso-ramosissimus , ramis arcuato- 

 patulo-erectis. — Peru 13. O. Spruceana. 



11.0. elatior Prog. in Mart. Fl. Brasil. XII. 2. (1877) 504, t. 106, f. 2. — O. 

 alta Pohl ex Prog. in Mart. Fl. Brasil. XII. 2. (1877) 50 4. — O. ramosa Pohl ex 

 Prog. 1. c. — Äcetosella elatior (Prog.) O. Kuntze, Rev. Gen. I. (1891) 92. — Erecta 

 vel stricta, 40 — 50 cm alta. Caulis basi 2V2 — 3l A mm crassus, sublignosus, atro- 

 brunneus vel -purpureus, inferne glaber, superne pubescens, simplex, fere e basi satis 

 dense foliatus et pedunculis ornatus. Folia alterna vel rfc dissolute fasciculata, tri— 

 foliolata, petiolata; foliola puberula, usque 45 cm longa et 18 mm lata, lanceolata vel 

 ovato-lanceolata, basi et apice db acuminata, exs. membranaceo-papyracea, opaca, 

 ecallosa; medium petiolulatum petiolulo 10 mm longo; petiolus usque 35 mm longus, 

 foliolo medio aequilongus vel eo parum brevior, exs. Y2 mm crassus, gracilis, basi vix 

 dilatatus, pubescens. Pedunculi axillares, usque 7 cm longi, exs. y 2 — z /\ mm crassi, 

 =b stricti, sicut pedicelli puberuli vel tomentosi, apice bifurcati; rami usque 20 mm 

 longi, apice umbellas 1 — 4-floras contractas gerentes. Bracteae 1 mm longae, lineari- 

 subulatae, acutae, pubescentes. Pedicelli 3 mm longi, tenues. Flores 8 mm longi, tri- 

 morphi. Sepala lanceolata, obtusa, ecallosa, glabra, 4 mm longa. Corolla sepalis 1 3 /4 — 

 2-plo longior, pallide rubella vel lutescens; petala e basi angustata spathulata, antice 

 rotundata, alba. Filamenta maiora in formis microstylosis dense puberula, minora glabra 

 Ulis vix J-plo breviora; in formis macrostylosis filamenta maiora glabriuscula, minora 



