What is it? Ulmus parviflora (lacebark elm) in August growing at NYBG
The NYBG Plant Information Service identifies thousands of plants every year for curious plant lovers. When we identify a plant for you, we would like to give you as much specificity as possible; different varieties of a plant genus need different care, are suitable for different locations and fulfill different roles in a garden or landscape. In some cases, we are looking for minor clues to identify your plant as nearly as we are able.
Plant identification is frequently based on experiential imprinting -- recognizing it because we've seen it before. Given the number of plant species globally and the even greater number of cultivars and hybrids in cultivation, it is impossible for anyone at NYBG to actually see or learn, let alone remember, everything. Fortunately, plant identification can also be based on diagnosis.
Diagnostic features vary from species to species, but in general we will be looking for the following vegetative features in your photos: habit (herb, shrub, tree, vine), leaf composition (simple or compound), phyllotaxy or leaf arrangement (alternate, opposite, whorled), leaf margin (lobed, toothed, entire), stipules present or absent (paired outgrowths at the base of the petiole, often deciduous but then leaving scars), venation (pinnate or palmate), and more cryptic features like smell (spicy, resinous, minty, foetid, bell peppery, green beany, etc.), latex or sap present (whitish, sometimes yellowish or copious but clear), pellucid dots, or stellate hairs (and other pubescence types). If reproductive features (flowers and fruits) are available, it is important to note merosity (number of petals, especially), if the flowers are sympetalous or apopetalous (petals fused or free), hypanthium present or not (fused base of sepals, petals, and filaments, notable as a ring of tissue usually with the sepals, petals and stamens attached along the rim), stamen number & arrangement, carpel number, gynoecium syncarpous or apocarpous, ovary inferior or superior. (Please see the "What Should I Photograph?" tab above if you are interested in suggestions on how to get the right photos.)
A few, well-shot photographs are usually our best resource for making an identification. Sometimes we need to ask for additional views of a surprising part of the plant to differentiate between similar species or cultivars. But a good start for getting the identification you are looking for is to send a few clear photographs of the most commonly telling parts of a plant.
Clarity: It is very hard to identify a plant from a blurry image. Sometimes the foreground or background is in focus, but not the actual plant and this makes it too difficult to see the details needed to make an accurate identification. Sometimes we receive a photo where the plant is too far away to see any detail and despite the picture being clear and in focus, zooming in to see details causes the image to become pixilated.
It is most helpful to see a variety of clear views of the plant: from a distance so we can see the growing form, a clear close up of leaves, top and underside, and their arrangement on the stem, clear details of other notable features like fruit, bark, buds, twigs and flowers. Make sure the sharpest focus is on the target. Details must be recognizable in the final result.
Distance: If the picture is of a flower, the flower should be at a comfortable distance that allows it to nearly fill the frame without needing to zoom in for details . The same is true for leaves, bark and fruit. If taking a picture of the entire plant, do not take it from so far away that the plant looks small in the image. It will not show details and zooming in will make it blurry.
Sense of Scale: When possible, place an object in the picture, such as a person, a coin or ruler, to give a sense of scale.
Light: Try to take pictures on a cloudy day, or early in the day or late in the afternoon. Pictures taken in bright sunshine often look washed out or lose detail. Avoid taking pictures at night with a flash as it can also wash out some color and details.
Site Wide Shot: A wide shot showing the site where the plant is located can often provide important clues, such as if the plant was in a low lying boggy area or up on a dry slope.
Tangled Plants: Make sure the image is trained on the plant in question. Plants that are crowded or tangled with other plants can be difficult to distinguish from each other. Sometimes the plant in question is growing through another plant causing confusion about what is what. If necessary, gently pull back the plant that is in the way to get a good shot of the unknown plant.
Location: Was the plant in a public garden, someone’s yard or balcony, or growing wild in the woods or along a road? We receive questions from around the world so please let us know the country, state and city in which you took your photos. A plant's location can give essential details.
Time of Year: Many plants only flower at a specific time of the year for a certain period of time. So, knowing if the picture was taken recently or if it was taken weeks or months ago can help to narrow things down.
Odors: Does the plant emit any scent? Do the leaves or twigs have any odor and do they have any notable sap when crushed or scratched?
Characteristics noted but not captured by the photos: Do the leaves have transluscent or colored dots when held up to the light? What else did you notice that you feel is not explained in the photo - is the color true?
Do not embed pictures into the body of an email if you can avoid it. Embedded images prevent us from zooming in to see details.
We are looking forward to receiving your questions about plant identification!
The New York Botanical Garden (2016) by 
Photographic Atlas of Botany and Guide to Plant Identification by 
Magnificent Trees of the New York Botanical Garden by 
Photographing Plants and Gardens by 
The Field Guide to Photographing Flowers by 
