Alnus cordata (Loisel.) Duby, Bot. Gall. 1: 423 1828. (Syn: Alnus cordata Desf. [Invalid]; Alnus cordata f. parvifolia Callier; Alnus cordifolia Ten.; Alnus cordifolia var. rotundifolia Regel; Alnus macrocarpa Req. ex Nyman; Alnus neapolitana Savi; Alnus nervosus Dippel; Alnus obcordata C.A.Mey. ex Steud. [Spelling variant]; Alnus rotundifolia Bertol. [Illegitimate]; Betula cordata Loisel.);
NE. Corse, S. Italy (As per WCSP)
Alnus cordata (Italian alder) is a species of alder in the family Betulaceae, native to southern Italy (including Sardinia and Sicily). It is also considered native in Albania and Corsica, and naturalized in Belgium, Spain, and the Azores.
It is a medium-sized tree growing up to 25 m tall (exceptionally to 28 m), with a trunk up to 70–100 cm diameter. The leaves are deciduous but with a very long season in leaf, from April to December in the Northern Hemisphere; they are alternate, cordate (heart-shaped), rich glossy green, 5–12 cm long, with a finely serrated margin.
The slender cylindrical male catkins are pendulous, reddish and up to 10 cm long; pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn 2–3 cm long and 1.5–2 cm broad, dark green to brown, hard, woody, and superficially similar to some conifer cones. The small winged seeds disperse through the winter, leaving the old woody, blackish ‘cones’ on the tree for up to a year after.
Like other alders, it is able to fix nitrogen from the air. It thrives on much drier soils than most other alders, and grows rapidly even under very unfavourable circumstances, which renders it extremely valuable for landscape planting on difficult sites such as mining spoil heaps and heavily compacted urban sites. It is commonly grown as a windbreak.
The Italian Alder makes a medium to large bonsai, a quick grower it responds well to pruning with branches ramifying well and leaf size reducing quite rapidly.
(From Wikipedia on 8.2.16)
Tree For ID : California : 16OCT14 : AK-3 : 9 posts by 3 authors.
A tall tree, seen in Fremont on 28th Sept.
Or, it could be an Alnus sp.
Alnus cordata of family Betulaceae?
I think you are right! It looks like Alnus cordata to me, too.
close up of leaves and the fruits would help
It was a tall tree, this is the closest I could get.