Table 1 in Isotrema putalengense, a new species of Aristolochiaceae from northern Vietnam and two new combinations in Isotrema

Table 1. Morphological differences between Isotrema putalengense and close species (based on Hwang 1981; Ma 1989; Hwang et al. 2003; Zhu et al. 2019e; Wang et al. 2020b).
CharactersI. putalengenseI. ovatifoliumI. pseudoutriformeI. utriformeI. wardianumPetioledensely pubescent, 3-4.5 cm longvillous, 3-5 cm longdensely pubescent, 2-5 cm longglabrous, 4-8 cm longdensely villous, 3-5 cm longLaminalanceolate to slightly pandurate, 15-20 × 4-6 cm, with auriculate base, adaxially sparsely pubescent, abaxially pubescentovate, 5-13 × 4-8 cm, with cordate base, abaxially villous, adaxially glabrescent (densely villous when young)ovate to narrowly ovate, 10-22 × 7-13 cm, with cordate base, adaxially sparsely pubescent, abaxially densely pubescentovate-lanceolate, 10-17 × 3-4 cm, with auriculate base, adaxially glabrouslanceolate, 12-16 × 3-4 cm, with auriculate base, adaxially subglabrous to glabrousPedicel2.5-3 cm long3-6 cm long1.8-5 cm long4-6 cm long1-2.5 cm longBracteolestriangular, inserted on basal half of pedicelovate, inserted on basal 1/2 of pedicelovate, inserted on basal half and/or distal half of pedicelovate-lanceolate, inserted above distal half of pedicelovate, inserted on basal half of pedicelFlower positionon old woody stemsaxillaryaxillary, sometimes on stemsaxillaryaxillaryPerianth limbcylindric, ovoid in front view, straightly extended from upper tube, purple, 2.5-2.7 cm long × 1.2-1.3 cm in diameter, abaxially densely yellowish to brown hirsutesubcylindric, straightly extended from upper tube, purple-red, 1.5-2.5 cm long × 1-1.5 cm in diameter, abaxially densely off-white villouscylindric, forming obtuse angle with upper tuber, light yellow, 2-3 cm long × 1-1.7 cm in diameter, abaxially sparsely villousovoid, straightly extended from upper tube, yellow-green, 1-2 cm long × ca. 1 cm in widest diameter, abaxially sparsely pilose to glabrouscylindric, oblong in front view, forming obtuse angle with upper tube, purple with yellow apex, ca. 2.5 cm long × 0.9 cm in diameter, abaxially densely yellow villousLimb lobeswide trianglesubrounded or nearly truncatetriangle or wide triangleovate-deltatewide trianglePerianth throatca. 3-4 mm wideca. 2.5 mm wideca. 6 mm wideca. 1 mm wideca. 2-3 mm wideUtricleindistinct from lower tube, 7-8 mm in diameter, light yellowindistinct from lower tube, 3-5 mm in diameter, purple-redindistinct from lower tube, ca. 7-9 mm in diameter, light yellowindistinct from lower tube, 3-4 mm in diameter, yellow-greendistinct from lower tube, 5 mm in diameter, light yellowTube notchU-shapedV-shapedU-shapedV-shapedV-shapedUpper tube6-7 mm long × 5-6 mm in diameter, purpleca. 3-5 mm long × 3-4 mm in diameter, purple-red3-4 mm long × 6-8 mm in diameter, light yellowca. 3-5 mm long × 5-6 mm in diameter, yellow-greenca. 10 mm long × 6 mm in diameter, purpleAnnulushemisphericalflatring-like, raisedconvexhemisphericalStigma lobestruncate to slightly obtuse, irregularly toothedobtuse, entireround, entireobtuse, entireobtuse, entire