=17.= =Quercus marilándica= Muenchhausen. Black Jack Oak. Plate 56. Mature trees generally 10-30 cm. in diameter; bark resembles that of a gnarled black oak; twigs generally scurvy-pubescent the first year; leaves on petioles from nearly sessile to 2.5 cm. long, usually less than a cm. long, blades 7-15 cm. long, broadly obovate, often almost as wide as long, narrowly rounded at the base, with three primary lobes at the apex, sometimes with two small lateral lobes, the apex is sometimes almost rounded and the position where the lobes usually occur is indicated by three primary veins which end in a bristle, the apex of the leaf is generally about equally divided into three lobes by two very shallow rounded sinuses, the lobes are rounded or merely acute; sometimes the terminal lobes develop a secondary lobe, leaves very pubescent both above and beneath when they first appear, becoming smooth and glossy above at maturity, and remaining more or less pubescent beneath; acorns sessile or nearly so, single or in pairs; nuts ovoid or oblong, 1-1.5 cm. long, broadly rounded at the base, rounded or somewhat conic at the apex, enclosed for about half their length in the cup-shaped cup; scales blunt, not closely appressed, pubescent on back, light reddish-brown; kernel bitter. [Illustration: Plate 56. QUERCUS MARILANDICA Muenchhausen. Black Jack Oak. (× 1/2.)] =Distribution.=--New York to Nebraska, south to Florida and west to Texas. In Indiana it is known to the author from Sullivan, Greene and Clark Counties and southwestward. It has been reported from Jefferson County by Barnes which is no doubt correct. Doubtful records are those by Brown for Fountain County, Miami County by Gorby, and Phinney's report for the area of Delaware, Jay, Randolph and Wayne Counties. It has been reported for the vicinity of Chicago by Higley and Raddin. It may be local on sterile, sandy ridges of the northern part of the State, but very local if it does occur. It is generally found in very poor soil on the crest of ridges associated with black and post oak. However, it has been found in Greene, Sullivan and Knox counties on sand ridges and at the base of sand ridges associated with black and post oak. The species has a very limited mass distribution and is only occasionally found and in colonies of a few trees each. =Remarks.=--Trees too small and scarce to be of any economic importance. ULMÀCEAE. The Elm Family. Trees or shrubs with simple, alternate, 2-ranked, petioled leaves; sepals 3-9, petals none, stamens as many as the sepals and opposite them, stigmas 2. Branchlets with solid pith; leaves with primary veins parallel; flowers borne on the twigs of the preceding season 1 Ulmus. Branchlets with chambered pith at the nodes; leaves 3-veined at the base; flowers borne on the twigs of the season 2 Celtis. 1. ÚLMUS. The Elms.