This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
[Echinospermum Sw.; Lehm. Asperif. 113. 1818.]
Annual or perennial rough-pubescent or canescent erect branching herbs, with alternate narrow entire leaves, and small or minute blue or white flowers, in terminal bracted or bractless racemes. Calyx deeply 5-cleft or 5-parted, the segments narrow. Corolla salver-form or funnelform, the tube very short, the throat closed by 5 scales, the lobes obtuse, spreading, imbricated in the bud. Stamens included; filaments very short. Ovary 4- lobed; style short. Nutlets 4, erect or incurved, laterally attached to the receptacle, at length separating, the margins or backs armed with stout often flattened barbed prickles, the sides usually papillose or tuberculate. [Diminutive of the Latin lappa, a bur.]
About 40 species, mostly natives of the north temperate zone. Besides the following, several others occur in western North America. Type species: Lappula Myosdtis Moench.
Racemes bracted; fruiting pedicels not deflexed.
Prickles in 2 rows on the margins of the nutlets, distinct.
1. L. Lappula.
Prickles in 1 row on the margins, more or less confluent.
2. L. texana.
Racemes bracted only at the base; fruiting pedicels deflexed. Stem-leaves ovate-oblong, the basal cordate; fruit globose.
3. L. virginiana.
Leaves oblong, oblong-lanceolate or linear; fruit pyramidal. Flowers 3"-5" broad; fruit about 3" broad.
4. L. floribunda.
Flowers 1-2 broad; fruit about 2" broad.
5. L. deflexa.