216 JOURNAL OF THE ARNOLD ARBORETUM (vol. hi 



Acer stenolobum (Sect. Platanoides), sp. nov. 



Arbor vel frutex; gemmae pluriperulatae perulis ciliatis ramuli tenues, 

 annotini brunneo-grisei, vetustiores grisei, lenticellis paucis parvis in- 

 structs Folia profunde trilobata, 3-4.5 cm. lata et 2.5-3.5 cm. longa, base 

 fere truncata lobis subaequilongis angulo circiter 60° divergentibus, 

 anguste oblongo-lanceolatis 4-7 mm. latis marginibus fere parallelis, 

 integris obtuse acuminatis vel apicem versus paucidentatis, subtus ad 

 basin in axillis nervorum villosa et margine initio sparse ciliata, ceterum 

 glabra, laete viridia; petioli graciles 1.5-3 cm. longi, glnbri. Flores 

 andro-polygami, ut videtur lutescentes. graciliter et longe pedicellati, in 

 corymbis glabris multifloris cum pedunculo gracili 1-2 cm. longo circiter 

 5 cm. longis et 3-4 cm. latis terminalibus in apice ramulorum foliis 4 

 instructorum; sepala 5, ovalia 1.5-2 mm. longa, obtusa, margine vel inter- 

 dumtantum apice longe et sparse ciliata; petala lineari-oblonga vel ob- 

 longa, saepe inaequalia, sepalis subaequilonga vel paullo minora, glabra; 

 stamina 5, inter lobos disci profunde lobati inserta, antheris ovalibus 

 circiter 1-1.2 mm. longis; filamenta in floribus masculis sepalis duplo 

 longiora, in flore fertili stamina sepalis subaequilonga; ovarium minute 

 pilosulum; stylus ad medium fissus stigmatibus papillosis revolutis; in 

 floribus masculis ovarium valde reductum stylis erectis brevibus basi con- 

 natis vel nullum; alae in fructibus juvenilibussuberectae basi vix constrictae 

 et plus minusve incurvae. Fructus maturu desideratur. 



China. Shensi: west of Yenan Fu, Wm. Purdom, No. 337, 1910. 



This very distinct species belongs in the section Platanoides Pax, 

 but is easily distinguished from all other species of this group by the small 

 deeply 3-lobed leaves with very narrow lobes of nearly equal length, the 

 lateral ones wide-spreading and sometimes nearly horizontal . It seems 

 nearest to A. pictum Thunb., A. truncatum Bge. and A. tenellum Pax, but 

 differs from them not only in the shape of the leaves, but also in the 5 

 exserted stamens, in the puberulous ovary and in the longer style. 



Acer cappadocicum Gled. f. rubrum Nash in 5 Jour. New York Bot. 



Gard. xx. 87 (1919), nomen, as var. — A. laetum 2. rubrum Kirchner in 



Petzold & Kirchner, Arb. Muse. 193 (18G4). — A, colchicum rubrum Hort. 

 ex Kirchner, 1. c. (1864), as synon. — A. laetum var. rubrum Ruprecht in 

 Mem. Acad. Sci. St. Petersb. ser. 7, xv.no. 2, 281 (Fl. Caucas.) (1869).— 

 A. pictum var. rubrum Nicholson in Gard. Chron. ser. 2, xvi. 375 

 (1881). — A. Lobelii subsp. lactam var. colchicum f. hortlcola Pax in Bot. 

 Jahrb. VII. 237 (1886). — A. laetum var. colchicum 3. rubrum hort. apud 

 Schwerin in Gartenfl. xlii. 459 (1893). — A. laetum var. colchicum f. 

 hortlcola Pax in Engler, Pflanzenr. iv-163, 48 (1902). — A. cappadocicum 

 f. hortlcola Relider in Sargent, PI. Wilson, i. 86 (1911). 



As the correct combination for this form of A. cappadocicum 

 was published by Nash without the citation of any synonyms, the synonyms 

 are cited here to show that there can be no doubt that the varietal name 

 rubrum and not hortlcola has the priority. 



