Key to the Genera of the Cichorieae Tribe of the Asteraceae Family of the New York New England Region. Introduction

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1 Introduction The Cichorieae Tribe: The Asteraceae family of plants is one of the largest plant families in the world, conservatively estimated to include over 23,000 species, with some estimates as high as 30,000 species. Plant taxonomists divide very large plant families into smaller groups of species called tribes. The Cichorieae tribe, named after the genus Cichorium (chicory), is one of the largest tribes of the Asteraceae, with a geographic center of diversity in Europe, North Africa and the Middle East. Many of the species found in eastern North America are European introductions. Shared Characteristics of Cichorieae: Species within a given tribe are hypothesized to share certain morphologic characters which distinguish them from members of other tribes. Species in the Cichorieae are recognized by their milky sap and ligulate flower heads. Many species in this tribe have leaves that are basally disposed, with at least some basal leaves present during flowering. For some species, stem leaves if present, are alternate. The corollas of the vast majority of these species are yellow. A few have blue, orange or white corollas. Genera Included in this Key: Cichorium, Crepis, Hieracium, Hypochaeris, Krigia, Lactuca, Lapsana, Mycelis, Nabalus (Prenanthes), Picris, Pilosella, Scorzoneroides (Leontodon), Sonchus, Taraxacum and Tragopogon. Approach: Ideally, a key to these genera should be based on characteristics of their fruits (cypselae). However, inclusion of only fruit characteristics would likely make it more difficult for the student to envision what these plants actually look like. Accordingly, characteristics of leaves and flower heads are also included in this key. It should be noted as well that the species represented in this 7-state region are but a subset of a much larger group of species, many of which are found in other parts of North America, or on other continents. Morpholgic diversity found in species from other regions or continents may not be reflected in this key. Exceptions: Sonchus appears twice in the key because some populations have glandular involucral bracts, while other populations are glabrous. Picris appears twice in this key because some plants have leaves with lobed margins but other plants have leaves without lobes. Hieracium appears twice in the key because some Hieracium species have leafy stems, but no basal leaves (at flowering), whereas other species have leaves that are primarily basal. Glossary: Definitions of technical terms used in this key can be found in the glossary at the end of this document. Copyright Arieh Tal, 2016 Page 1

2 1a. Stems possess 5 or more well-developed (evident) leaves. 2a. At least some leaves of the plant have lobed margins. 3a. Involucral bracts possess minute stalked glands (glandular hairs). 4a. Pappus consists entirely of minute scales. Cichorium 4b. Pappus consists entirely of bristles. 5a. Lowermost (outer) involucral bracts are distinctly different in form and size from the inner involucral bracts. Cypselae are not flattened. Crepis 5b. Lowermost (outer) involucral bracts differ from inner bracts in size only, typically being smaller, but otherwise are similar in form. Cypselae are evidently flattened. Sonchus 3b. Involucral bracts do not possess stalked glands, though hairs of other types may be present. 6a. Cypselae lack pappus. Lapsana 6b. Pappus consists of a set of slender, hairlike or feather-like (i.e., plumose) bristles. 7a. Involucral bracts are spreading and pubescent with bristly hairs and or forked hairs. Picris 7b. Involucral bracts are appressed and glabrous. 8a. Flower heads are relatively large, containing 80 or more florets. Sonchus 8b. Flower heads are relatively small, containing fewer than 50 florets. 9a. Flower heads are pendulous at anthesis. Nabalus (Prenanthes) 9b. Flower heads are erect or spreading at anthesis. 10a. Flower heads contain 5 florets. Mycelis 10b. Flower heads contain more than 5 florets. Lactuca. Copyright Arieh Tal, 2016 Page 2

3 2b. Leaf margins of the plant are unlobed (though teeth may be present). 11a. The plant's leaves are linear or narrowly lanceolate (i.e., grass-like) Tragopogon 11b. The plant's leaves are wider: lanceolate, oblanceolate or elliptic (i.e., not grass-like). 12a. Involucral bracts are not glandular. Picris 12b. Involucral bracts typically possess some or many stalked glands (except Hieracium umbellatum). Hieracium 1b. Stems possess fewer than 5 leaves (typically 0-3 leaves), which may be similar to basal leaves but smaller, or they may consist of minute, scale-like bracts. That is, the stem appears scape-like at flowering. 13a. Basal leaves have lobed margins. 14a. Pappus consists of both minute scales and slender, hairlike bristles. Krigia 14b. Pappus consists only of bristles. 15a. The receptable bears thin, membranous scales (chaff, paleae). Hypochaeris 15b. The receptacle lacks scales. 16a. Cypselae possess a long, thin beak. Pappus is of slender, hair-like bristles. Taraxacum 16b. Cypselae lack a beak. Pappus is of feather-like (plumose) bristles. Scorzoneroides (Leontodon) 13b. Basal leaves have unlobed and untoothed margins, though minute mucros are present on margins in some species. (Hieracium murorum leaf margins may have coarse "teeth"). 14a. Cypsela body is usually 2.0 mm or less in length; ribs of cypselae extend slightly above the flat apex of the cypsela. Pilosella 14b. Cypsela body is slightly greater than 2.0 mm in length; ribs of cypselae do not extend above the flat apex of the cypsela. Hieracium Copyright Arieh Tal, 2016 Page 3

4 Glossary Alternate: an arrangement of leaves or flowers on a stem or branch, in which only one leaf or flower attaches to the stem at a node. Anthesis: the flowering period. Apex: the tip, or the furthest point on a structure, such as a stem, branch or leaf. (plural: apices) Appressed: lying flat or nearly flat against another plant part, as for example, hairs lying flat against a stem or surface of a leaf. Basal: located at or near the base of a plant or other structure, such as a stem. Basally disposed: a tendency to be located toward the base of the plant, as for example, when all or most leaves are basal leaves, as in a basal rosette. Beak: an appendage that projects from the tip of a structure, sometimes relatively long and thin; e.g., a beak at the tip of a cypsela. Bilateral symmetry: exists if hypothetical division of the corolla of a flower into two equal halves can occur in only one plane. Bract: a small leaflet at the base of a flower, pedicel or inflorescence. (Bracteate: having bracts.) Chaff: bract-like scales borne on the receptacles of flower heads of some species in the Asteraceae. They often serve to subtend individual florets. (syn.: palea) Corolla: all of the petals of a flower, collectively. Cypsela: a dry, indehiscent (not splitting at maturity), one-seeded fruit from an ovary that is attached below the petals and sepals. (pl. cypselae) Elliptic: a 2-dimensional object in the shape of an ellipse; i.e., longer than broad and tapering to approximately the same degree on both ends. Erect: growing straight upwards, or nearly so. Flower head: in Asteraceae, a collection of florets (typically more than one) borne on a common receptacle & subtended by an involucre. (syn.: capitulum) Glabrous: lacking hairs entirely. Gland: a minute structure, sometimes hair-like when borne on a stalk, exuding a sticky or oily substance. Glandular: bearing glands. Involucre: in the Asteraceae, the collection of small bracts that subtends the florets of a flower head. Involucral bract: in the Asteraceae, a small bract comprising part of an involucre. (syn. phyllary) Lanceolate: lance-shaped, much longer than wide, with the broadest portion of the blade toward the base. Ligule: literally, a "little tongue". The widened and usually flattened, 5-lobed portion of the corolla of a ligulate floret. The 5 "petals" are fused into 1 blade, with 5 lobes at tip. Ligulate: in the Asteraceae, a bisexual floret with a ligule. All florets of a ligulate flower head are morphologically similar, each including a ligule, a pistil and stamens. Linear: extremely thin and narrow, many times longer than wide. Lobe: a portion of a structure, such as a leaf or corolla, that is larger than a tooth, and projects outward or downward. Margin: an edge of a surface, such as a leaf, sepal or petal. Mucro: a short, slender point occurring along the margin or at the tip of a structure, such as a leaf. Oblanceolate: lance-shaped, much longer than wide, with the broadest portion of the blade toward the tip. Pappus: in the Asteraceae, the hairs, bristles and/or scales borne at the summit of a cypsela. (plural: pappi) Peduncle: the stalk of an inflorescence. In the Asteraceae, the stalk bearing a flower head, or set of flower heads. Pendulous: drooping, or hanging downward. Plumose: feather-like; often used to refer to pappus bristles that are minutely branched, thus appearing feather-like. Pubescent: a general term for describing plant hairiness; sometimes used more specifically to refer to short, soft hairs. Ray: in the Asteraceae, a floret that is located along the circumference of a flower head, and possesses a widened and flattened, 0- to 4-lobed corolla. Receptacle: in the Asteraceae, the expanded, apical portion of a peduncle that bears the florets, the ovaries (cypselae when in fruit), and sometimes chaff. Scales: a thin, membranous structure, usually lacking chlorophyll, sometimes similar in shape to a leaflet. Scape: a peduncle that arises from the base of a plant and lacks well-developed leaves. Very small leaflets or bracts may be present on scapes, however. Spreading: leaning outwards from the point of attachment. Subtend: Positioned below and close to another structure, such as leaf, branch or flower. Copyright Arieh Tal, 2016 Page 4

5 Copyright Arieh Tal, 2016 Page 5