POP ULUS 
9 
Section II. A/GEIROS 
Aigeiros Duby Bot. Gall. 427 (1828); Ascherson und Graebner Syn. iv, 15 et 31 (1908); Aegiri Dode 
op. cit. p. 34. 
For characters, see page 5. 
Series of Aigeiros. 
Series iii. Nigrae (see below). Laminae acute to acuminate, usually with no glands at the 
junction of the petiole, margin not ciliate. Catkins shorter and rather more slender than in Delto'ideae. 
Stamens about 1 2 — 20. Capsules more elongated. 
Series iv. Delto'ideae (p. 11). Laminae acute, some or all on each twig with 1 — 2 greenish 
glands at or near the junction of the petiole. Catkins longer and stouter than in Nigrae. Stamens 
about 30 — 60. Capsule subspherical. 
Series iii. Nigrae 
Nigrae nobis; Nigra Dode op. cit. p. 37. 
For characters, see above. 
British species of Nigrae 
4. # P. italica (see below). Branches strongly fastigiate. Young twigs and petioles glabrous. 
Laminae smaller than in P. nigra , abruptly acuminate. Stamens about 20. 
5. P. nigra (p. 10). Lower branches spreading or arched. Young twigs and petioles glabrous 
or hairy. Laminae acuminate. Slametis about 8 — 16. 
4. # POPULUS ITALICA. Lombardy Poplar. Plates 9, 10 
PopulllS italica Moench Baiime Weissenst. 79 (1785); P. nigra var. italica Duroi Harbk. Baumz. ii, 
141 (1772); P. pyramidalis [Rozier Cours d'Agric. (1786) ex] Dode op. cit. 50 (1905); P. fastigiata Fougeroux 
in Mem. Agric. ( Soc . Roy. Paris') for 1786, pt. i, 82 (1787); P. dilatata Aiton Hort. Kew. iii, 406 (1789); 
P. pyramidata Moench Meth. PI. 339 (1794); P. nigra var. pyramidalis Spach in Ann. Sci. Nat. sdr. 2, 31 (1841); 
Wesmael in DC. Prodr. xvi, pt. ii, 328 (1868); P. nigra race italica Ascherson und Graebner Syn. iv, 41 (1908). 
leones : — Camb. Brit. FI. ii (1913). Plate p. Long shoot. Plate 10. (a) Twig with staminate catkins. 
(b) Bracts (enlarged). ( c ) Staminate flower (enlarged). ( d ) Leaf-bud (enlarged). Huntingdonshire (E. W. H.). 
(e — h) See *P. italica x nigra var. genuina (below). 
Tree strongly fastigiate, attaining a height of about 30 or 35 m., rarely with suckers. Bark 
less black than in P. nigra , often brownish or greyish in the upper part of the tree, smooth. 
Winter-buds very acute. Branches strongly fastigiate, short, slender ; young ones glabrous. Leaves 
unfolding in late March or early April, about two weeks earlier than in P. nigra. Stipules as in P. nigra. 
Petioles glabrous, shorter than the laminae. Laminae smaller than in P. nigra , subdeltoid to sub- 
rhomboidal, crenations bigger and more irregular than in P. nigra , apex abruptly acuminate. Staminate 
catkins 3 or 4 cm. long ; mid-March, about 2 — 4 weeks earlier than P. nigra. Bracts more irre- 
gularly laciniate than in P. nigra. Stamens about 20. Pistillate plants not known. 
The statement is commonly made that the Lombardy poplar differs from the black poplar only in habit ; but we find 
the differences of the two plants to be indefinite in number. These differences apply to the habit, to the shape of the 
buds and leaves, to the time of unfolding of the leaves and of the catkins, to the time of leaf-fail, to the time of 
flowering, and to the structure of the different parts of the flower. We have no hesitation therefore in regarding P. italica 
and P. nigra as distinct species. If P. italica is merely a fastigiate form of P. nigra, we can only say that it is a fastigiate 
form of some variety of P. tiigra which we have never seen. Dode (op. cit. 50) distinguishes the following “ species ” of 
fastigiate poplars in the series Nigrae : — P. pyramidalis, P. bethmontiana , P. thevistina, and P. thracia (= P. pannonica 
Reichenbach Icon. t. 619, fig. 1276). The species (P. italica) is thus very variable; but outside Botanic Gardens we have 
only seen the first of these forms in this country. 
Commonly planted in the lowlands of the British Isles, but, like all our poplars, thriving best in damp soils. 
It is difficult to state where this tree is indigenous : it is certainly not so in the Plain of Lombardy. 
Ascherson und Graebner (op. cit. p. 43) regard its home as in “eastern Europe; Orient, eastwards to Turkistan; 
north-western Asia ; northern Africa.” 
*P. italica x nigra var. genuina comb. nov. ; P. pyramidalis x nigra Figert in Deutsche Bot. Monat. 
v, 109 (1887) ; P. nigra var. typica x var. italica C. K. Schneider Handb. Laubh. i, 6 (1906) ; P. nigra race typica x race 
italica Ascherson und Graebner Syn. iv, 43 (1908). 
M. II. 
2 
