Plant Families

Seed morphology is unique to each plant family, and the identification to a family level is the first step of seed identification. Identifying seeds will not only use the knowledge of seed morphology but also other closely related knowledge, such as plant taxonomy and nomenclature.  Here are resources that are complied by ISMA either from publicly accessible websites, or with the permission from authors.  The aim is to provide reliable sources to users who are interested in using these resources in their applications.

ISMA Editorial Board

Grass Spikelet Structures of Diagnostic Value

Deborah J. Lionakis Meyer
23 February 2022

An illustrated overview of the structure of grass spikelets, and their use in grass seed identification.

Grasses are one of the most recognizable and yet diverse plant families, and many of our most important economic crops are grasses. The structure of the grass spikelet is both extremely specialized and very diverse among the many members of the grass family. In this article, Deborah Meyer will walk you through the many variations of the grass spikelet, explaining the specific terminology used to describe grass floral structures and how these structures are modified to produce the vast array of grasses all around us. Click here to read more.

Other Resources

Fruit and Seed Family ID (

M. Islam, A. Miller, M. Maher, J. Scher, A. Redford, Nov. 2022

Identify fruits and seeds to family  (Currently includes only monocot families)


Fruits and seeds form the bulk of agricultural commerce and are common contaminants in commodities. If introduced, non-native species may naturalize, leading to devastating consequences for crops and wildlands, so correct identification of fruits and seeds is essential to safe trade. Fruit and Seed Family ID aids in identification of fruits and seeds to family. This first edition of the tool will focus on monocotyledon families, with all other seed plant families to follow. Fruit and Seed Family ID is intended for individuals working at ports of entry, state departments of agriculture, university extension services, and for anyone interested in fruit and seed identification.

Field identification of the 50 most common plant families in temperate regions

(including agricultural, horticultural, and wild species)  
Lena Struwe, 2017, Rugers, the State University of New Jersey.

Note: Listed characteristics are the most common characteristics; there might be exceptions in rare or tropical species. This compendium is available for free download without cost for noncommercial uses at The author welcomes updates and corrections.

Family Guide for Fruits and Seeds

Kirkbride, J.H., Jr., C.R. Gunn, and M.J. Dallwitz. 2006. United States Department of Agriculture (USDA), Agricultural Research Service.