ak ▁is ▁a ▁much ▁branch ed ▁ever green ▁shr ub ▁or ▁small ▁tree ▁up ▁to ▁ 1 0 ▁m ▁high . ▁Due ▁to ▁its ▁short ▁stat ure ▁( in ▁relation ▁to ▁other ▁o aks ) ▁it ▁is ▁sometimes ▁referred ▁to ▁as ▁the ▁d war f ▁o ak . ▁ ▁Its ▁leaves ▁are ▁simple , ▁ob ov ate ▁to ▁sub orb icular , ▁ 1 . 5 – 6 ( – 1 0 ) ▁cm ▁long , ▁ 1 – 5 ▁( – 8 ) ▁cm ▁wide , ▁gl ab r ous ▁and ▁sh ining ▁dark ▁green ▁above ▁and ▁dens ely ▁golden ▁or ▁brown ish ▁t oment ose ▁below , ▁with ▁ser rate ▁marg ins ▁and ▁raised ▁n ervation . ▁Le ave ▁pet i oles ▁are ▁strong , ▁ 6 – 1 0 ▁( – 1 2 ) ▁mm ▁long ▁and ▁pil ose . ▁Flow ers ▁are ▁un is ex ual ; ▁male ▁cat kins ▁are ▁green ish - yellow ▁forming ▁spread ing ▁or ▁p end ul ous ▁clusters ▁at ▁the ▁tips ▁of ▁the ▁branches ; ▁female ▁are ▁ax ill ary , ▁solit ary ▁or ▁in ▁groups ▁of ▁ 2 – 3 . ▁Ac orn s ▁are ▁narrow ly ▁ob ov ate ▁or ▁sub cy l ind rical , ▁usually ▁tap ering ▁towards ▁base , ▁ 2 – 2 . 5   cm ▁long ▁and ▁ 0 . 8 – 1 . 2   cm ▁wide , ▁with ▁a ▁wo ody ▁end oc arp ▁and ▁cup ule ▁with ▁strongly ▁rec ur ved ▁scales .