Holzapfel, S.; Lack, H. W. 1993: New species of Picris (Asteraceae, Lactuceae) from Australia. Willdenowia 23: 181–191.
Details
Details
Holzapfel, S.; Lack, H. W. 1993: New species of Picris (Asteraceae, Lactuceae) from Australia. Willdenowia 23: 181–191.
Article
Taxonomic concepts
Picris angustifolia subsp. merxmuelleri Lack & S.Holzapfel
Descriptions
Herba annua (vel perennis?), 50-120 cm alta. Caulis crassus, erectus, ramosus vel ramosissimus (apice interdum irregulariter umbellatim ramosus), tota longitudine pilis bihamatis ancoriformibus basi saepe rigidissimis obtectus. Folia basalia 10-20 cm longa, 1,0-2,5 cm lata, anguste lanceolata vel anguste ovata, breviter petiolata, margine mucronulata vel integra; folia caulina numerosa, (2)4-20 cm longa, (0,3)0,4-2,5 cm lata, lanceolata vel anguste lanceolata, petiolata vel sessilia; superiora sessilia, utrinque pilis bihamatis ancoriformibus rigidis, ad marginem etiam bifurcatis obtecta. Pedunculi erecti, 1-6 cm longi, nudi vel pilis bihamatis ancoriformibus obtecti, interdum squamis paucis squarrosis vel verticillatis, obovato-acutis vel lanceolatis obsiti. Capitula plura, ramos terminantia, ca. 30-45-flora, fructifera ca. 0,9-1,3 cm longa, ca. 0,5-0,6(0,7) cm diametro. Involucrum polyphyllum e squamis 28-40 lanceolatis, supra nudis, inferne semper pilis crassis vel gracilibus 0,3-0,6(1,5) mm longis, simplicibus rarissime bifurcatis vel bihamatis in serie singulari obsitis. Squamae exteriores 3- vel 4-seriatae erectae vel squarrosae vel reflexae, extimae 3,5-5,0(7,5) mm longae, 0,6-1,4(1,5) mm latae, longissimae 5,5-9,5 mm longae, 0,8-1,4(1,5) mm latae; squamae interiores 9,0-12,0(14,0) mm longae, (1,4)1,6-2,1 mm latae, squamis longissimis exterioribus subaequimagnae. Corollae 9,0-13,0 mm longae, in sicco ochraceae; ligula 5,0-9,0 mm longa, 1,0-2,0 mm lata, quinquedentata; tubus nudus vel apice sparse pilis tenuibus, simplicibus, brevibus obsits, antherae 1,3-2,0 mm longae; stylus 5,5-9,0 mm longus. Achenia conformia, brunnea, 4,0-5,2 mm longa (incl. cuspide), 0,8-1,1 mm diametro, anguste fusiformia, ad apicem gradatim in cuspidem brevem (0,4-0,9 mm longam) attenuata, longitudinaliter quinquecostata, transverse rugosa vel transverse costata (ca. 5,0-6,6 costae per mm longitudinis achaenii) et pappo 5,0-8,0 mm longo facile deciduo coronata. Radii pappi ca. 50-80, pinnulis multis longis dense obsiti (plumosi), basi in annulum conjuncti. Receptaculum nudum, alveolatum, ca. 3,5-,0 mm diametro. Squamae acheniis delapsis reflexae.
Identification keys
Key to the species of Picris in Australia
1.
Indumentum of mainly 2-hooked anchor hairs, pappus of all achenes of equal length
Indumentum of mainly 3 or 4-hooked anchor hairs, pappus of marginal achenes clearly shorter than of central achenes
2.
Achenes 3,2-4,1 mm long, abruptly ending in a very short, 0,1-0,2 mm long cuspis; achene segments densely ribbed with 9,5-11,8 ribs per mm achene length; fruiting heads 0,9-1,1 cm long, 0,8-1,1 cm in diameter
Achenes 2,9-10,7(12,5) mm long, gradually tapering into a cuspis, very variably, 0,1-6,8(7,4) mm long; achene segments sparingly to moderately densely ribbed with 3,3-6,7(9,0) ribs per mm achene length; fruiting heads 0,7-2,2 cm long, (0,4)0,5-1,8 cm in diameter
4.
Hairs on midrib in more than one line, mass of hairs covering the whole involucrum
Hairs on midrib in a single line
5.
Outer involucral bracts in 2-3 rows, rarely longest outer bracts longer than 2/3 of length of innermost bracts, usually markedly shorter; all bracts straight; outer bracts upright to sometimes slightly squarrose, not as wide as inner bracts
Outer involucral bracts in 2-4 rows, usually many outer bracts longer than 2/3 of length of innermost bracts, often almost as long as inner bracts; outer bracts straight or recurved, upright to distinctively squarrose, not as wide or wider than inner bracts
6.
Flowering capitula 0,6-0,7 cm long, 0,3-0,5 cm in diameter, fruiting capitula 0,7-0,9 cm long; plant with large number (30-80 or more) of small capitula on short and slender peduncules; scales on achene ribs strongly upright
Flowering capitula 0,8-1,50,6) cm long, (0,3)0,4-1,0 cm in diameter, fruiting capitula 0,8-1,8 cm long; plant with few (or one) to usually less than 40 capitula on usually long and slender peduncules; scales on achene ribs flat or upright
7.
Achenes 3,9-5,2 mm long; cuspis 0,3-0,9 mm long, 1/6-1/14 of total length of achene; fruiting capitula 0,9-1,3 cm long
Achenes 5,0-8,0 mm long; cuspis 0,7-3,0 mm long, 1/3-1/5 of total length of achene, rarely less (to 1/7) and then fruiting capitula 1,3-1,5 cm long and peduncules with numerous bracts appearing to descend from involucrum
8.
Involucral bracts all naked, outer bracts slightly squarrose, straight
Involucral bracts always with a single line of short and strong to slender hairs along midrib on abaxial side of bracts, outer bracts straight and upright to conspicuously squarrose and recurved
10.
Outer involucral bracts squarrose and recurved, numerous, often appearing to descend on peduncule; peduncules with few to numerous bracts close to capitulum or over whole length of peduncule, midrib on abaxial side of involucral bracts naked or with short hairs; achenes with a slender cuspis
Outer involucral bracts upright to slightly squarrose, tips recurved, involucrum compact, not descending on peduncule, peduncules with 0-2 bracts close to capitulum, midrib on abaxial side of involucral bracts always naked, achenes with a rather strong cuspis
11.
At least some outer involucral bracts wider than Inner bracts, broadly obovate, ovate or cordate, 1,5-5,0mm wide
Outer involucral bracts not as wide as inner bracts or rarely of same width, lanceolate to narrowly obovate or linear, 0,5-1,10,6) mm wide
12.
Margin of outer involucral bracts with conspicuous, often bristly hairs towards base, midrib on abaxial side of bracts always naked
Margin of involucral bracts always naked; midrib on abaxial side of involucral bracts naked or with hairs
Reproduced with permission from http://www.bgbm.org/BGBM/library/publikat/willdenowia.htmWilldenowia and Botanic Garden and Botanical Museum Berlin-Dahlem.
Cited scientific names
Metadata
28f6b235-8a6d-4172-a4e7-0bb757dda5b2
reference
Names_Plants
