Div inside a table-cell

how to make the div 100% height?

HTML

<div id="pictures">
	<article class="entry picture">
		<div class="entry picture">
			<img class="picture" src="./images/150x150.jpg" width="150" height="150"></img>
		</div>
		<div class="entry picture infobox">
			<a href="#" class="entry">
				<h3 class="entry picture headline">contents_0 alpha headline</h3>
				<div class="view picture">
					<span class="comments_amount">5</span>
					<span class="articlenk info">Bild zeigen</span>
				</div>
			</a>
		</div>
	</article>
	<article class="entry picture"><div class="picture wrapper">
		<div class="entry picture">
			<img class="picture" src="./images/150x71.jpg" width="150" height="71"></img>
		</div>
		<div class="entry picture infobox">
			<a href="#" class="entry">
				<h3 class="entry picture headline">contents_0 beta headline</h3>
				<div class="view picture">
					<span class="comments_amount">5</span>
					<span class="pictures info">Bild zeigen</span>
				</div>
			</a>
		</div></div>
	</article>

	<article class="entry picture">
		<div class="entry picture">
			<img class="picture" src="./images/150x200.jpg" width="150" height="200"></img>
		</div>
		<div class="entry picture infobox">
			<a href="#" class="entry">
				<h3 class="entry picture headline">contents_0 gamma headline</h3>
				<div class="view picture">
					<span class="comments_amount">5</span>
					<span class="pictures info">Bild zeigen</span>
				</div>
			</a>
		</div>
	</article>
	
	<article class="entry picture">
		<div class="entry picture">
			<img class="picture" src="./images/150x150.jpg" width="150" height="150"></img>
		</div>
		<div class="entry picture infobox">
			<a href="#" class="entry">
				<h3 class="entry picture headline">contents_0 delta headline</h3>
				<div class="view picture">
					<span class="comments_amount">5</span>
					<span class="pictures info">Bild zeigen</span>
				</div>
			</a>
		</div>
	</article>

	<article class="entry picture">
		<div class="entry picture">
			<img class="picture"...

CSS

div#pictures {
    display: flex;
    flex-flow: row wrap;
}

article {
    flex: 1 1 50%;
    border: 1px solid;
    box-sizing: border-box;
    position: relative;
}

div.infobox {
    position: absolute;
    bottom: 0;
}